问题 选择题

如下图所示,原来置于黑暗环境中的绿色植物移植光下,CO2的吸收量发生了变化。据图判断下列叙述中正确的是 (  )

A.曲线AB段表示绿色植物没有进行光合作用

B.曲线BD段表示绿色植物仅进行进行光合作用

C.在B点显示绿色植物光合作用和呼吸作用速率相等

D.整段曲线表示,随着光照强度递增光合作用递增,呼吸作用停止

答案

答案:C

题目分析:从图中可以看出,曲线AB段光照强度已经大于零点位置,说明该段绿色植物是见光的,只是光照强度弱,光合作用的速率小于呼吸作用的速率,但也在进行光合作用,A错误;曲线BD段既进行光合作用,又进行呼吸作用,并且光合作用速率大于呼吸作用速率,B错误;B点时,绿色植物吸收二氧化碳和释放二氧化碳相等,所以在B点显示绿色植物光合作用和呼吸作用速率相等,C正确;通过以上分析可得出D错误,故选C

阅读理解

Islamabad, Pakistan, June 22nd---Two mountain climbers surprisingly survived (幸免于) a fall of over 500 feet on the 25,530-foot mountain in Pakistan, Saturday. The two climbers were climbing an ice-covered wall of the mountain when they suddenly lost their footing and fell about 560 feet to a narrow snow-covered ledge(悬崖突出部分) below. “We were lucky that ledge was there,” said the climbers, “Otherwise, we would have fallen over 2,000 feet.” If the ledge had not been there, the two climbers almost certainly have met their death. “It’s a wonder,” the climbers said, “that we landed on the ledge, and the snow was loose enough to cushion(缓冲) our fall. We’re thankful that we survived.”

When a reporter asked them if they planned to give up mountain climbing after their narrow escape(九死一生), the two climbers replied, “Not at all. We’ll be going back up there just as soon as we get out of the hospital.”

小题1:The mountain climbers survived because _____.

A.they had fallen only 500 feet down

B.of the ledge and the loose snow on it

C.of their strong bodies

D.they were very good climbers小题2:If there had not been the snow-covered ledge, _____.

A.they wouldn’t have fallen down

B.they would have them wounded

C.they would have lost their lives

D.they would fall into the deep snow小题3: How high was the ledge from the foot of the mountain?

A.2,560 feet high

B.2,000 feet high

C.25,530 feet high

D.More than 1,400 feet high小题4:Choose the right order which shows what happened to the two climbers.

a. talked with a reporter           b. lost their footing 

c. was sent to a hospital           d. fell to a ledge     

e. started to climb an ice-covered wall

A.b-d-c-e-a

B.e-d-b-c-a

C.e-b-d-c-a

D.a-c-b-d-e小题5:What are the two climbers going to do when they get well again?

A.To go ahead with the climbing

B.To give up mountain climbing

C.To write an article for the newspaper

D.To return to the snow-covered ledge

计算题