填空题

Questions 47 to 56 are based on the following passage.
The researchers put all the plants in a greenhouse to grow under normal conditions for forty days. Then, for fifteen days after that, the plants did not receive any (47) . The normal plants lost their green color. Finally, they lost their leaves. But the researchers say the (48) plants kept their leaves and their (49) .
After the fifteen dry days, all the plants were watered again for a week. The transgenic plants returned to (50) growth, and their seed production was close to normal But the other plants all died.
Rosa Rivera says the transgenic plants kept a (51) high water level. They also (52) to produce energy during the dry period, although at a reduced level. The amount of seeds they produced was close to normal. In addition, the researchers found that the plants could (53) on only thirty percent of the normal amount of (54) water. Yield loss was minor, they said.
The (55) appeared late last year in the Proceedings of the National Academy of Sciences. The University of California has applied for patent (56) for the technology. The researchers expect to move forward with field testing of the transgenic tobacco in late August. They hope for similar results with crops like tomatoes, rice, wheat and cotton.

• A) similarI) color
• B) keepJ) production
• C) water K) level
• D) relatively L) findings
• E) normal M) continued
• F) survive N) protection
• G) gained O) irrigation
• H) transgenic