阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。
A
1. The word “homework” in the first paragraph refers to ______.
A. work that is given by teachers for students to do at home
B. Websites such as and
C. tools and suggestions offered by websites
D. market research and informal research
2. The underlined sentence in the passage means that you’d better ask for a raise ______.
A. when the employer has a normal pulse rate
B. when the employer is in a good mood
C. when the company has a good financial situation
D. when the company’s practices are more flexible
3. Which of the following is NOT true?
A. The employer will give you a raise because of your personal reasons.
B. You should show them that you’re worthy of a salary increase.
C. You can tell your boss the exact number of salary increase you want
D. Schedule a meeting with your boss but don’t push too hard.
4. It can be inferred in the last paragraph that ______.
A. If your boss won’t give you a raise, you’d better take fewer responsibilities.
B. It is a wise way to get a raise by letting your boss know you are doing more.
C. Only if you find a proper time to talk with your boss will you get a raise.
D. You should schedule a meeting within a few months to discuss the matter again.
B
Here’s one number to keep in mind during your next cell phone conversation: 50. A new experiment shows that spending 50 minutes with an active phone pressed up to the ear increases activity in the brain. This brain activity probably doesn't make you smarter. When cell phones are on, they emit (发出) energy in the form of radiation that could be harmful, especially after years of cell phone usage. Scientists don't know yet whether cell phones are bad for the brain. Studies like this one are attempting to find it out.
The 47 participants in the experiment may have looked a little strange. Each one had two Samsung cell phones attached to his or her head — one on each ear. The phone on the left ear was off. The phone on the right ear played a message for 50 minutes, but the participants couldn't hear it because the sound was off.
With this set-up, the scientists could be sure they were studying brain activity from the phone itself, and not brain activity due to listening and talking during a conversation. After 50 minutes with two phones strapped to their heads, the participants were given PET scans.
The PET scan showed that the left side (the side with the phone turned off) of each participant's brain hadn't changed during the experiment. The right side of the brain, however, had used more glucose, which is a type of sugar that provides fuel to brain cells. These right-side brain cells were using almost as much glucose as the brain uses when a person is talking. This suggests th at the brain cells there were active ― even without the person hearing anything. That activity, the scientists say, was probably caused by radiation from the phone.
Henry Lai, who works at the University of Washington in Seattle, is uncomfortable with the data related to cell phones. Holding a cell phone to your ear during a conversation is “not really safe,” Lai told Science News. Lai is a bioengineer at the University of Washington in Seattle. He wrote an article about the new study for a journal, but he did not work on the study. Bioengineers bring together ideas from engineering and biology.
For those who don't want to wait to find out for sure whether cell phones are bad for the brain, there are ways to talk more safely. You can have short and sweet conversations, use a
