[单项选择]Can we see (1) the earth is a globe Yes, we can, when we watch a ship that sails out to sea. If we watch closely, we see that the ship begins (2) . The bottom of the ship disappears first, and then the ship seems to sink lower and lower, (3) we can only see the top of the ship, and then we see nothing at all. What is hiding the ship from us It is the earth. Stick a pin most of the way into an orange, and (4) turn the orange away from you. You will see the pin disappear, (5) a ship does on the earth.

A. until
B. since
C. after
D. by the time

[单项选择]Can we see (1) the earth is a globe Yes, we can, when we watch a ship that sails out to sea. If we watch closely, we see that the ship begins (2) . The bottom of the ship disappears first, and then the ship seems to sink lower and lower, (3) we can only see the top of the ship, and then we see nothing at all. What is hiding the ship from us It is the earth. Stick a pin most of the way into an orange, and (4) turn the orange away from you. You will see the pin disappear, (5) a ship does on the earth.

A. if
B. where
C. that
D. when

[填空题]We can see with our

[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. we are sick
B. we can’t see clearly
C. we wear glasses
D. we burst into tears

[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 r
A. we are sick
B. we can’t see clearly
C. we wear glasses
D. we burst into tears