各类机械设备安装、牢固、周正、水平，不准（）移动设备。雷雨、暴雨禁止作业。

在某化学反应中，下列说法正确的是（）。

A.参加化学反应的各种物质，等于反应后生成的各种物质

B.参加化学反应的反应物，等于反应后生成的生成物

C.参加化学反应物的各种物质重量之和，等于反应后生成的各种物质重量之和

D.参加化学反应的各种反应物重量之和，等于反应后生成的各种生成物重量之和

试述细菌性角膜炎的病因、临床表现及治疗原则。

若银行利率为8%，按复利计息，现存款10000元，10年内每年年初的等额提款为( )元。

A．1000
B．1380
C．1490
D．1600

探索文学必须立足于文学活动的整体，当然相对稳定的是（）

A.世界

B.文学阅读

C.理论家

D.文学作品

The produce departments of the future may look like nothing on earth, and with good reason. Chinese scientists have been growing tomatoes the size of softballs, cucumbers as long as baseball bats and other outsize fruits and vegetables, using seeds that have been shot into space. The seeds are then exposed to seven types of extraterrestrial conditions, from zero gravity and cosmic radiation to subatomic particles. (46) As these space veggies grow back on earth, they are selected for desirable traits--bulk, appearance or certain nutrients--then bred through successive generations to ensure that the mutations are consistent.
Chinese scientists don’t understand exactly how a trip into space alters the seeds’ DNA and yields such effects, but it’s not just size that changes. (47) Tong Yichao, whose firm, the Beijing Flying Eagle Green Foods Group, has been sending seeds and seedlings aboard Chinese spacecraft since 1999, says it has grown space tomatoes with 27 percent more of the antioxidant beta carotene than ordinary ones, and six-foot-tall cotton plants that produce longer, more flexible threads. Using conventional methods, "a scientist might create just three new plants in his lifetime," says Tong. "We’ve developed more than 50 since 1999."
(48) A dozen or so Chinese firms are paying up to $ 45 000 a gram to place various flora aboard satellites and manned spacecraft. The long-term goal: to feed more people and help endangered species escape extinction. To date, nearly 3 000 botanical species-including garden vegetables, medicinal herbs and flowers--have been sent into orbit and brought back to earth.
(49) The commercial promise of China’s space veggies has yet to, er, bear fruit. It’ s legal to sell the cosmic produce, and commercial farms have purchased some space plants. But most are being developed in labs or experimental greenhouses because no one wants to go to market before the safety and quality of the produce have been established. Even so, the idea of space flora is proving irresistible to a novelty-loving Chinese public. (50) When Tong displayed a handful of monster space eggplants--the largest of which weighed more than four pounds--at an expo, one disappeared before the show opened. Hot stuff, for sure.