this is a cat
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五年级上册英语书第3课知识点总结归纳
一、词汇
新单词
animal:动物(例:I like animals very much. 我非常喜欢动物。)
cat:猫(例:I have a cat at home. 我家里有一只猫。)
dog:狗(例:The dog is playing with a ball. 狗正在玩球。)
elephant:大象(例:Elephants have big ears. 大象有大耳朵。)
fish:鱼(例:I like to eat fish. 我喜欢吃鱼。)
giraffe:长颈鹿(例:The giraffe has a long neck. 长颈鹿有一个长脖子。)
horse:马(例:The horse is running fast. 马跑得很快。)
lion:狮子(例:The lion is the king of the jungle. 狮子是丛林之王。)
monkey:猴子(例:Monkeys like to climb trees. 猴子喜欢爬树。)
tiger:老虎(例:Tigers are very strong animals. 老虎是非常强壮的动物。)
相关词汇
fur:皮毛(例:Cats have soft fur. 猫的皮毛很柔软。) - 2 -
tail:尾巴(例:The dog wags its tail when it's happy. 狗高兴的时候会摇尾巴。)
leg:腿(例:The elephant has four strong legs. 大象有四条强壮的腿。)
paw:爪子(例:The lion has sharp paws. 狮子有锋利的爪子。)
二、语法
名词复数
大多数动物名词是可数名词,要用复数形式表示多个动物。例如:cats(猫),dogs(狗),elephants(大象)。
不规则复数形式的名词要特别注意,如:fish(鱼)的单复数同形;mouse(老鼠)的复数是mice。
第1页 共4页 第2页 共4页 形容词性物主代词和名词性物主代词练习题
1。 This is my book. __ are over there.
A. Your B. Yours C. You
D。 Mine
2. Whose pen is it? It's __。
A. her B。 hers C。 she
D。 his
3。 __ bag is new and __ is new, too.
A. Our, he B。 Ours, his C. My,
his D. My, her
4。 This room is ours, and that one is __.
A。 they B。 them C. theirs D. their
5。 Whose pencils are there? They’re __。
A。 my B. me C。 mine D。 our
6。 Is the new watch __? Yes, it's __.
A. you, me B。 yours, mine C. your, my
D。 your, mine
7. Whose shoes are these? They are __。
小学英语看图说话
HEN system office room 【HEN16H-HENS2AHENS8Q8-HENH1688】 一、 动物篇
二、 人物篇
三、 水果篇
四、 季节篇
1. Look! This is a cat. It’s
black and brown. Her eyes
are big. Her ears are big,
too. Her nose is small, Her
tail(尾巴) is very long.
Her favorite food is fish.
She is two years old. She
can run fast. She is very
cute. I like cat very much.
2. I have a happy family.
There are three people in
my family. They are my
father, mother and me. Look.
This is my father. He is 35
years old. He is a doctor.
And this is my mother. She
is 33 years old. She is a
teacher. I love my family.
3. From this picture, we can
see many fruits. For
example(例如), peach, banana, lemon, cherry,
grape, pear and watermelon.
(还可以介绍每种水果的颜色哦)
My favorite fruit is grape.
It is purple and it is
EtherCAT实时以太网
EtherCAT(以太网控制自动化技术)是一个以以太网为基础的开放架构的现场总线系统,EtherCAT名称中的CAT为Control Automation Technology(控制自动化技术)首字母的缩写。最初由德国倍福自动化有限公司(Beckhoff Automation GmbH) 研发。EtherCAT为系统的实时性能和拓扑的灵活性树立了新的标准,同时,它还符合甚至降低了现场总线的使用成本。EtherCAT的特点还包括高精度设备同步,可选线缆冗余,和功能性安全协议(SIL3)。
Ether CAT(Ethernet for Control Automation Technology)是一种实时以太网现场总线系统。Ether CAT具有速度快,布线容易的特点:且具有兼容性和开放性;适合于快速控制的应用场合。
Ether CAT的工作原理
以太网是一种802.3 基带总线局域网,采用载波侦听多路访问/冲突检测(CSMA/CD)介质访问控制方式。实时以太网Ether CAT 技术采用了主从介质访问方式,在基于Ether CAT 的系统中,主站控制从站发送或接收数据。主站发送数据帧,从站在数据帧经过从站时读取相关报文中的输出数据。同时,从站的输入数据插入到同一数据帧的相关报文中。当该数据帧经过所有从站并与从站进行数据交换后,由Ether CAT 系统中末端从站将数据帧返回,如图1。
Ether CAT 的性能
Ether CAT 支持各种拓扑结构,如总线型、星型、环形等,并且允许Ether CAT
系统中出现多种结构的组合。支持多种传输电缆,如双绞线、光纤、光导总线等,以适应于不同的场合,以提升布线的灵活性。
Ether CAT 采用了精准的同步时钟系统。系统中的数据交换完全是基于纯硬件机制,由于通讯采用了逻辑环结构(借助于全双工快速以太网的物理层),主站时钟能简单、精确地确定各个从站传播的延迟偏移。分布时钟均基于主时钟进行调整,在网络范围内使用精确且确定的同步误差时间基。