Have you ever dreamed about a trip to space? Seeds(种子)of some vegetables and crops are a lot luckier than you, as they have travelled to space and back．
China is among the three countries in the world that carry out agricultural(农业的)research in space．The others are Russia and the U．S．Since 1987, China has sent about 1000 kinds of seeds into space．These include green peppers, tomatoes, cucumbers, carrots and rice．Even on China's first manned spacecraft Shenzhou V there were some seeds from Taiwan．
“Conditions(条件)in outer space such as radiation(辐射)and low gravity can cause big changes in the seeds, ” said Chinese researcher Jin Xing．
But not all seeds are better after going to space．After returning to the earth, the best seeds are chosen．These seeds produce much more and also grow faster than normal seeds．As the safety of genetically modified(转基因)food is still being talked about, some people are not sure about the safety of these “space vegetables” because some of their genes(基因)are changed during the trip to space．
But Jin holds the more hopeful view．He said, “Unlike genetically modified crops, no new genes are introduced to the space vegetables, so they are surely safe．”
Space vegetables are better than normal vegetables．For example, space tomatoes stay fresh for twenty days, which is one week longer than normal tomatoes．Another popular space vegetable is the peppers．Space peppers have 20 per cent more vitamin C than normal peppers．
Researchers are considering holding a tomato festival．By the time people will be able to enjoy about 30 different kinds of space tomatoes on their dining tables．
So far, the Chinese Academy of Sciences has set up three space vegetable base fields, one of which is in Shenzhen while the others are in Beijing and Jiangsu Province．
(1)
What will happen when seeds of some vegetables are sent to space and carried back?
[ ]
A．
Some of their genes are changed．
B．
They are all better than before going to space
C．
No changes are caused in the seeds．
D．
They all produce much more and grow faster．
(2)
Why does Jin Xing have no doubt about the safety of the space vegetables?
[ ]
A．
Because the seeds sent to space stay the same．
B．
Because the seeds sent to space are the best．
C．
Because no new genes are brought into them．
D．
Because space vegetables are luckier．
(3)
Which of the following statements is TRUE?
[ ]
A．
Genetically modified food is completely safe．
B．
The space vegetables don't belong to genetically modified food in some ways．
C．
About 1000 kinds of seeds were sent into space on Shenzhou V．
D．
Seeds back from space must be planted in special rooms controlled by computers．
(4)
What is the underlined word “cucumber” in the second paragraph?