某同学用刚煮沸后冷却的水养鱼，不久，鱼却死了．下列能比较合理

搜题请搜索小程序“爱下问搜题”

问题选择题

某同学用刚煮沸后冷却的水养鱼，不久，鱼却死了．下列能比较合理地解释此现象的叙述是（　　）

A．水中的细菌在煮沸的过程中被杀死

B．水中溶解的氧气在煮沸的过程中逸出而减少

C．煮沸后刚冷却的水中溶人更多的二氧化碳

D．煮沸后刚冷却的水中溶人更多的氮气

答案

答案：B

单项选择题 A1/A2型题

不易合并胎位异常的是（）。

A.双胎

B.胎盘早剥

C.羊水过多

D.前置胎盘

E.骨盆狭窄

补全对话，情景问答

补全对话。

A=TonyB=Lingling

A:What did you do yesterday?

B:I went to listen to a  1 about animals in  2.

A:It sounds very  3.

B:Yes.Do you know the Wolong Panda  4?

A:Of course I know.What's wrong?

B:The 5 thing is to hear  6  7 animals are in danger all over the world.

A:It's  8 to think about that.

B:We  9 to 10 our tigers,turtles and snakes.

A:Yes,you are right.