USACO 2017年首轮月赛铂金级题2
推箱子
贝茜和她的朋友们发明了一种新游戏。这个游戏名副其实，但不是特别有创意。他们称做“在不移动草垛的前提下，在谷仓周围推箱子推到指定的位置”的游戏(如果你觉得有点绕口，往下看这个游戏规则时，你应该会想到一些类似的游戏名字)。
这个谷仓可以模式化成一个N×M的矩形网格。有些单元格堆满草垛。贝茜占据了其中一个单元格，一个大木箱在另一个单元格。一个单元格不能同时容纳贝茜和盒子，而且它们也无法进入堆满草垛的单元格。
只要前方没有草垛存在，贝茜可以在东南西北四个方向上移动。如果她要进入有大木箱的房间，这个房间里的木箱将会沿着她进来的方向移到前面的房间。如果前面的那个房间里堆满草垛，贝茜就无法移动了。其中一个特定的单元格作为终点。贝茜的目标是把箱子推到那个地方。
给定谷仓的布局，包括木箱和牛的起始位置，以及木箱的目标位置，判断是否能够赢得这场比赛。
注意:这个问题允许512MB的内存使用，高于默认的256MB。
输入格式(文件pushabox.in):
第一行有三个数字N，M和Q。其中，N代表网格的行数，M代表网格的列数。
1≤N≤1500
1≤Q≤50,000
接下来的N行，其中(.)表示空单元格、(#)表示堆满草垛的单元格、贝西的起始位置(A)和木箱的初始位置(B)。
接下来的Q行，每个行都有一对整数（R，C）。对于每一对坐标，你要判断是否能够从初始状态开始到达谷仓的第R排，第C列的单元格。最上面一行是1，最左边一行是1。
输出格式(文件pushabox.out):
Q行，每一行均为字符串“是”或“否”。
样例输入:
5 5 4
# # .# #
# #. # #
A.B..
# #. # #
# # .# #
3 2
35
1 3
53
样例输出:
NO
YES
NO
NO
把箱子推到(3,5)位置，奶牛只需要向右移动3个空间。其他三个位置均无法实现。
2017年12月英语六级考试真题试卷附答案(完整版第3套) Part I Writing (30 minutes) Directions: For this part, you are allowed 30 minutes to write an essay commenting on the saying "Help others, and you will be helped when you are in need." You can cite examples to illustrate your views. You should write at least 150 words but no more than 200 words. ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ Part Ⅰ Writing Be Generous with Your Help When it comes to the topic of help, we are frequently told that, "Help others, and you will be helped when you are in need. '' Simple as the saying is, it implies the importance of helping others in need. What I learn from the remark, in short words, is that helping others is helping yourself. Examples can easily be found to make this point clearer. The story of the ant and the dove is a case in point. An ant slipped into the river when drinking along the river. A dove heard his cries for help and threw him a leaf, which helped the ant float back to the bank. After a few days, a hunter was raising his gun to the dove as she was building her nest. Seeing this, the ant ran quickly to bite the hunter's leg. The dove heard the hunter's scream and flew away. All in all, this example indicates that when we offer our help to others, we are leaving a way open for the future. Helping others is a virtue, and we should take some measures to carry forward this virtue and do others a favor. Only in this way can we build a loving and harmonious society. Part II Listening Comprehension (30 minutes) 说明：由于2017年12月六级考试全国共考了2套听力，本套真题听力与前2套内容完全一样，只是顺序不一样，因此在本套真题中不再重复出现。 Part III Reading Comprehension (40 minutes) Section A Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once. Many European countries have been making the shift to electric vehicles交通工具and Germany has just stated that they plan to ban the sale of vehicles using gasoline汽油and diesel柴油as fuel燃料by 2030. The country is also planning to reduce its carbon footprint碳排放by 80-95% by 2050, O26sparking点火、导致 a shift to green energy in the country. Effectively, the ban will include the registration of new cars in the country as they will not allow any gasoline L27powered vehicle to be registered after 2030. Part of the reason this ban is being discussed and H28 implemented is because energy officials see that
2017年6月英语六级真题及答案(部分)
2017年6月英语六级真题 作文一：国内国外上大学 Directions: Suppose you are asked to give advice on whether to attend college at home or abroad, write an essay to state your opinion. You are required to write at least 150 words but no more than 200 words. 参考答案 Nowadays, there has been a heated discussion as to a better choice between attending college at home and abroad. Views on the topic vary greatly among people from different walks of life. Some believe that it is a better choice to study in domestic colleges, but others consider it better to study abroad. I totally agree with the latter idea for the reasons presented below. To begin with, it harms the society in that the greater the competition is, the higher the recruitment requirements will become. Therefore, with experiences of studying abroad, graduates will become more competitive in job hunting. Furthermore, it is beneficial to the students themselves to study abroad. Without the choice to pursue overseas study, many great scholars today would never have achieved such great success. From my perspective, it is crucial that the government should encourage people to pursue overseas study. Also it is crucial that people should understand the meaning and value of attending college abroad. Only in this way can we achieve greater success. 作文二：文科还是理科 Directions: Suppose you are asked to give advice on whether to major in humanities or science, write an essay to state your opinion. You are required to write at least 150 words but no more than 200 words. 参考范文： Living in a world which is full of changes and challenges,we are confronted with new problems every single day. Of all the issues, one might concern the high school graduates the most, and it is if there are two options: to major in science or humanities. As for me, I prefer the latter. Why,you may wonder, should I prefer to major in humanities. The reasons responsible for it can be listed as follows . Among the most important reasons cited by people is that to major in humanities，directly or indirectly，can not only enrich our basic knowledge about the diversified culture but also sharpen one’s insight in daily routine，which is of great importance in one’s growth. What’s more, to study humanities can give us an independent personality and a deeper vision towards the world, if it were not for those two attributes, how could we achieve great goals in this dog-eat-dog world. Above all, in such a society where emphasis，more often than not，is laid on the depth of one’s thought, to choose humanities as one’s major, must be the best way .
目录 2017年6月大学英语四级真题及答案(完整版一) (1) 快速对答案 (14) 2017年6月大学英语四级真题及答案(完整版二) (14) 快速对答案 (28) 2017年6月大学英语四级真题及答案(完整版三) (28) 快速对答案 (37) 2017年6月大学英语四级真题及答案(完整版一) Part I Writing (25 minutes) (请于正式开考后半小时内完成该部分，之后将进行听力考试) Directions:For this part, you are allowed 30 minutes to write an advertisement on your campuswebsite to sell a computer you used at college. Your advertisement may include its brand, specifications/features, condition and price, and your contact information.You should write at least 120 words but no more than 180 words. Part II Listening Comprehension (30 minutes) Section A Directions:In this section, you will hear three news reports. At the end of each news report, you will hear two or three questions. Both the news report and questions will be spoken only once. After you hear questions, you must choose the best answer from the four choices marked A), B), C) and D). Then mark the corresponding letter onAnswer Sheet 1 with a single line through the centre. 注意：此部分试题请在答题卡1上作答。 Questions 1 to 2 are based on the conversation you have just heard. 1.A) The man in the car was absent-minded.
2017年12月大学英语六级考试真题（第3套） Part I Writing (30 minutes) （请于正式开考后半小时内完成该部分，之后将进行听力考试） Directions: For this part, you are allowed 30 minutes to write an essay commenting on the saying "Help others, and you will be helped when you are in need " You can cite examples to illustrate your views. You should write at least 150 words but no more than 200 words. Part II Listening Comprehension (30minutes)说明：由于2017年12月六级考试全国共考了2套听力，本套真题听力与前2套内容完全一样，只是顺序不一样，因此在本套真题中不再重复出现。 Part III Reading Comprehension (40 minutes) Section A Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once. Question 26 to 35 are based on the following passage. Many European countries have been making the shift to electric vehicles and Germany has just stated that they plan to ban the sale of vehicles using gasoline and diesel as fuel by 2030. The country is also planning to reduce its carbon footprint by 80-95% by 2050, ___26___ a shift to green energy in the country. Effectively, the ban will include the registration of new cars in the country as they will not allow any gasoline ___27___ vehicle to be registered after 2030. Part of the reason this ban is being discussed and ___28___ is because energy officials see that they will not reach their emissions goals by 2050 if they do not ___29___ a large portion of vehicle emissions. The country is still ___30___ that it will meet its emissions goals, like reducing emissions by 40% by 2020, but the ___31___ of electric cars in the country has not occurred as fast as expected. Other efforts to increase the use of electric vehicles include plans to build over 1 million hybrid and electric car battery charging stations across the country. By 2030, Germany plans on having over 6 million charging stations ___32___. According to the International Business Times, electric car sales are expected to increase as Volkswagen is still recovering from its emissions scandal. There are ___33___ around 155,000 registered hybrid and electric vehicles on German roads, dwarfed by the 45 million gasoline and diesel cars driving there now. As countries continue setting goals of reducing emissions, greater steps need to be taken to have a ___34___ effect on the surrounding environment. While the efforts are certainly not ___35___, the results of such bans will likely only start to be seen by generations down the line, bettering the world for the future. A) acceptance I) incidentally B) currently J) installed C) disrupting K) noticeable D) eliminate L) powered E) exhaust M) restoration F) futile N) skeptical G) hopeful O) sparking H) implemented Section B Directions: In this section, you are going to read a passage with ten statements attached to it. Each statement contains information given in one of the paragraphs. Identify the paragraph from which the information is derived. You may choose a
文档编号：YLWK239517 2017 年6 月大学英语六级考试真题(第1 套) Part ⅠWriting (30 minutes) Directions: Suppose you are asked to give advice on whether to attend a vocational college or a university, write an essay to state your opinion. You are required to write at least 150 words but no more than 200 words. Part ⅡListening Comprehension (30 minutes) Section A Directions : In this section, you will hear two long conversations. At the end of each conversation, you will hear four questions. Both the conversation and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A), B), C) and D). Then mark the corresponding letter on Answer Sheet 1 with a single line through the centre. Questions 1 to 4 are based on the conversation you have just heard. 1.A) He would feel insulted. B) He would feel very sad. C) He would be embarrassed. D) He would be disappointed. 2.A) They are worthy of a prize. B) They are of little value. C)They make good reading. D) They need improvement. 3.A) He seldom writes a book straight through. B)He writes several books simultaneously. C)He draws on his real-life experiences. D)He often turns to his wife for help. 4.A) Writing a book is just like watching a football match. B)Writers actually work every bit as hard as footballers. C)He likes watching a football match after finishing a book. D)Unlike a football match, there is no end to writing a book. Questions 5 to 8 are based on the conversation you have just heard. 5.A) A chievements of black male athletes in college. B)Financial assistance to black athletes in college. C)High college dropout rates among black athletes. D)Undergraduate enrollments of black athletes. 6.A) They display great talent in every kind of game. B)They are better at sports than at academic work. C)They have difficulty finding money to complete their studies. D)They make money for the college but often fail to earn a degree. 7.A) About 15%. B) Around 40%. C)Slightly over 50%. D) Approximately 70%. 8.A) Coaches lack the incentive to graduate them. B)College degrees do not count much to them. C)They have little interest in academic work. D)Schools do not deem it a serious problem. Section B
2017年6月大学英语四级真题及答案(三) Part I Writing (30 minutes) (请于正式开考后半小时内完成该部分，之后将进行听力考试) Directions:For this part, you are allowed 30 minutes to write an advertisement on your campus website to sell some of the course books you used at college. Your advertisement may include a brief description of their content,their condition ,their price and your contact information. You should write at least 120 words but no more than 180 words. Part II Listening Comprehension (25 minutes) 说明：2017年6月大学英语四级考试全国共考了两套听力.本套的听力内容与第二套相同，因此本套听力部分不再重复给出。 Part ⅢReading Comprehension (40 minutes) Section A Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices, Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once. Questions 26 to 35 are based on the following passage. As if you needed another reason to hate the gym, it now turns out that exercise can exhaust not only your muscles, but also your eyes. Fear not, however, for coffee can stimulate them again. During (26)_______ exercise, our muscles tire as they run out of fuel and build up waste products. Muscle performance can also be affected by a (27)_______ called "central fatigue,” in which an imbalance in the
Passage One Questions 46 to 50 are based on the following passage. You may have heard that Coca-Cola once contained an ingredient capable of sparking particular devotion in consumers: cocaine. The “ coca” in the name referred the extracts of coca leaf that the drinks originator, chemist John Pemberton, mixed with his sugary syrup（姜汁）.At the time, coca leaf extract mixed with wi ne was a com mon tonic（滋补品），and Pembert on ' s sweet brew was a way to get around local laws prohibiting the sale of alcohol. But the other half of the name represents another ingredient, less infamous（名声不好的）,perhaps, but also strangely potent: the kola nut. In West Africa, people have long chewed kola nuts as stimulants, because they contain caffeine that also occurs naturally in tea, coffee, and chocolate. They also have heart stimulants. Historian Paul Lovejoy relates that the cultivation of kola nuts in West Africa is hundreds of years old. The leafy, spreading trees were planted on graves and as part of traditional rituals. Even though the nuts, which need to stay moist, can be somewhat delicate to transport, traders carried them hundreds of miles throughout the forests and grasslands. Europeans did not know of them until the 1500s, when Portuguese ships arrived on the coast of what is now Sierra Leone. And while the Portuguese took part in the trade, ferrying nuts down the coast along with other goods, by 1620, when English explorer Richard Jobson made his way up the Gambia, the nuts were still peculiar to his eyes. By the late 19th century, kola nuts were being shipped by the tonne to Europe and the US. Many made their way into medicines, intended as a kind of energy boost. One such popular medicinal drink was Vin Mariani, a French product consisting of coca extract mixed with red wine. It was created by a French chemist, Angelo Mariani, in 1863. So when Pemberton created his drink,it representedan ongoing trend. When cocaine eventually fell from grace as a beverage ingredient, kola-extract colas became popular. The first year it was available, Coca-Cola averaged nine servings a day across all the Atlanta soda fountains where it was sold. As it grew more popular, the company sold rights to bottle the soda, so it could travel easily. Today about 1.9 billion Cokes are purchased daily. It' s become so iconic that attempts to change its taste in 1985 sweetening it in a move projected to boost sales —proved disastrous, with widespread anger from consumers. -“CoClaocCalassic ,”returned to store shelves just three months after the “New Coke” was released. These days, the Coca-Cola recipe is a closely guarded secret. But it' s said to no longer contain kola nut extract, relying instead on artificial imitations to achieve the flavour. 你可能听说可口可乐曾经含有一种能够使消费者“死忠”的成分：可卡因名中的“ coca”指的是古柯叶的提取物，该饮料的创始人化学家约翰?彭伯顿用它与含糖的姜汁混合在一起。当时，古柯叶提取物与葡萄酒混合是常见的滋补品，而当地法律禁止出售含酒精饮料，彭伯顿的甜饮则避开了该法律。“cola ”代表另一种成分——可乐果：尽管名声不太好，但非常给力。 在西非，人们长期以来一直嚼着可乐果作为兴奋剂，因为它们含有咖啡因。咖啡因在茶、咖啡和巧克力中也天然存在。它们也有心脏兴奋剂。
2017年6月英语六级阅读真题及答案第1套选词填空 After becoming president of Purdue University in2013, Mitch Daniels asked the faculty to prove that their students have actually achieved one of higher education’s most important goals: critical thinking skills. Two years before, a nationwide study of college graduates had shown that more than a third had made no 26 gains in such mental abilities during their school years. Mr. Daniels needed to__27__ the high cost of attending Purdue to its students and their families. After all, the percentage of Americans who say a college degree is "very important" has fallen 28 in the last 5-6 years. Purdue now has a pilot test to assess students' critical thinking skills. Yet like many college " such as a graduate's ability to investigate and reason. However, the professors need not worry so much. The results of a recent experiment showed that professors can use __31__ metrics to measure how well students do in three key areas: critical thinking, written communication, and quantitative literacy. Despite the success of the experiment, the actual results are worrisome, and mostly __32__ earlier studies. The organizers of the experiment concluded that far fewer students were achieving high levels on critical thinking than they were doing for written communication or quantitative literacy. And that conclusion is based only on students nearing graduation. American universities, despite their global 33__ for excellence in teaching, have only begun to demonstrate what they can produce in real-world learning. Knowledge-based degrees are still important, but employers are still important, but employers are __34__ advanced thinking skills from college graduates. If the intellectual worth of a college degree can be __35__ measured, more people will seek higher education—and come out better thinkers. A. accurately B. confirm C. demanding D. doubtful E. drastically F. justify G. monopolized H. outcome I. predominance J. presuming K. reputation L. significant M. signify N. simultaneously O. standardized 答案：(26)L. significant (27)F. justify (28)E. drastically (29)D. doubtful (30)H. outcome (31)O. standardized (32)B. confirm (33)K. reputation (34)C. demanding (35)A. accurately 2017年6月英语六级阅读真题及答案第1套仔细阅读2篇 Open data sharers are still in the minority in many fields. Although many researchers broadly agree that public access to raw data would accelerate science, most are reluctant to post the results of their own labors online. Some communities have agreed to share online—geneticists, for example, post DNA sequence sat the GenBank repository (库) , and astronomers are accustomed to accessing images of galaxies and stars from, say, the Sloan Digital Sky Survey, a telescope that has observed some500 million objects—but these remain the excepti on, not the rule. Historically, scientists have objected to sharing for many reasons: it is a lot of work; until recently, good databases did not