题目内容：

If you need glasses to read this, you are among most of Chinese students. About four-fifths of high school students in China have poor eyesight(视力). And now more and more children in primary school need glasses, too.

Two main reasons can cause poor eyesight: too much time spent indoors studying and too little time spent outdoors playing. Reading and writing for hours and hours, sometimes in poorly lighted rooms, causes eyesight to weaken. But students have to do this because there is so much pressure on them to succeed in school. They have less time to enjoy the sun.

The sun, it turns out, is important in developing good eyesight. According to a study by Australian National University, Australian children and Chinese children have the same level of eyesight before they start school, but once they enter primary school, Chinese children only spend about an hour a day outside, while Australian children spend three to four hours each day in the sunshine. The result is that while about forty percent of Chinese primary school students need glasses, only three percent of Australian children do.

And poor eyesight at a young age can have serious long term influence. As you get older, your eyesight can worsen.

With all that in mind, don’t you think it’s time to give your eyes a break.

1.How many high school students have poor eyesight in China according to the reading

A. A half of them.    B. Three percent of them.

C. Forty percent of them.    D. Four-fifths of them.

2.Which can cause poor eyesight according to the reading

A. Like reading and writing very much.    B. Spend too much time enjoying the sun.

C. Spend too much time indoors studying.    D. Start primary school at a young age.

3.What can we learn from the third paragraph

A. Primary school studying can be very harmful to young students.

B. Australian children spend more time outdoors than Chinese children.

C. After primary school, children in China and Australia have the same eyesight.

D. Fewer Chinese primary school students have poor eyesight than Australian ones.