[填空题]We should be _____when we are doing our exercises .

[单项选择]
What were Jack and I doing when we saw the cat [A] Climbing the tree． [B] Playing in the garden． [C] Playing in the room．

[单项选择]—When shall we restart our business
—Not until we（）our plan.
A. will finish
B. are finishing
C. are to finish
D. have finished

[单项选择]（　） doing so, we decided to sell our new car at any price.
A. As
B. For
C. During
D. While

[填空题]When our laptop has some minor problems, we call dismantle it ourselves and repair it in order to save money and time.

[填空题]When we are trying to change our diet, we usually will be anxious because we are nervous about ______.

[单项选择]We should do more such exercises in the future, I think, （）those we did yesterday.
A. about
B. as
C. like
D. than

[单项选择]We often feel ____ when our efforts do not achieve what we hoped they would.
A. cut off
B. let down
C. put away
D. set up

[单项选择]When we arrived at the airport, we were told our flight _______ .
A. cancelled
B. had cancelled
C. has been cancelled
D. had been cancelled

[单项选择]When we placed our order ______ you we stressed that the goods would be required for winter sales in this country.
A. to
B. with
C. on
D. against

[简答题]

What are you doing when you aren’t doing anything at all If you said "nothing," then you have just passed a test in logic and failed a test in neuroscience. (46)When people perform mental tasks, different areas of their brains become active, and brain scans show these active areas as brightly colored squares on an otherwise dull gray background. But researchers have recently discovered that when these areas of our brains light up, other areas go dark. This dark network is off when we seem to be on, and on when we seem to be off. When we appear to be doing nothing, we are clearly doing something. But what
The answer, it seems, is time travel. (47)The human body moves forward in time at the rate of one second per second whether we like it or not, but the human mind can move through time in any direction and at any speed it chooses. Why did evolution design our brains to go wandering in time Perhaps it’s because an experi- ence is a terrib

[单项选择]When we can see well, we don’t think about our eyes very’ often. It is only when we cannot see perfectly that we come to see how important our eyes ale.
People who are nearsighted can only see things that are very close to their eyes. Many people who do a lot of close work, such as writing, reading and sewing, become nearsighted. Then they have to wear glasses in order to see distant things clearly.
People who are farsighted suffer from just the opposite problem. They can see things that are far away, but they have difficulty reading a book unless they hold it at arm’s length. If they want to do much reading, they must get glasses too.
Other people don’t see clearly because their eyes are not exactly the right shape. This, too, can be corrected by glasses. Some people’s eyes become cloudy because of cataracts (白内障). Long age these people often became blind. Now, however, it is possible to operate on the cataracts and remove them.
When night falls, colors become fain
A. Sometimes we can not see a thing because we look directly at it.
B. Sometimes we can not see a thing because we use the sides of eyes to see it.
C. The center of the eye is more sensitive than the sides of the eye after dark.
D. The center of the eye is as sensitive as the sides of the eye in daylight.