问题 判断题

观察洋葱片叶表皮细胞时,可以直接把稀碘液滴到材料上进行观察。        (    )

答案

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题目分析:制作洋葱表皮细胞临时装片的实验步骤简单的总结为:擦、滴、撕、展、盖、染、吸。

“擦”,用干净的纱布把载玻片和盖玻片擦拭干净;

“滴”,把载玻片放在实验台上,用滴管在载玻片的中央滴一滴清水;

“撕”,把洋葱鳞片叶向外折断,用镊子从洋葱鳞片叶的内表面撕取一块薄膜;

“展”,把撕取的薄膜放在载玻片中央的水滴中,用解剖针轻轻的把水滴中的薄膜展开;

“盖”,用镊子夹起盖玻片,使它的一端先接触载玻片上的液滴,然后缓缓放平;

“染”,在盖玻片的一侧滴加碘液.

“吸”,另一侧用吸水纸吸引,重复2~3次,使染液浸润到标本的全部。

故题干的叙述是错误的。

选择题
阅读理解

I was blind, but I was ashamed of it if it was known. I refused to use a white stick and hated asking for help. After all, I was a teenager girl, and I couldn't bear people to look at me and think I was not like them. I must have been a terrible danger on the roads, coming across me wandering through the traffic; motorists probably would have to step rapidly on their brakes. Apart from that, there were all sorts of disasters that used to occur on the way to and from work.

One evening, I got off the bus about halfway home where I had to change buses, and as usual I ran into something. "I'm awfully sorry," I said and stepped forward only to run into it again. When it happened a third time, I realized I had been apologizing to a lamppost. This was just one of the stupid things that constantly happened to me. So I carried on and found the bus stop, which was a request stop, where the bus wouldn't stop unless passengers wanted to get on or off. No one else was there and I had to try to guess if the bus had arrived.

Generally in this situation, because I hated showing I was blind by asking for help, I tried to guess at the sound. Sometimes I would stop a big lorry and stand there feeling stupid as it drew away. In the end, I usually managed to swallow my pride and ask someone at the stop for help.

But on this particular evening no one joined me at the stop; it seemed that everyone had suddenly decided not to travel by bus. Of course I heard plenty of buses pass, or I thought I did. But because I had given up stopping them for fear of making a fool of myself, I let them all go by. I stood there alone for half an hour without stopping one. Then I gave up. I decided to walk on to the next stop.

小题1:The girl refused to ask for help because she thought_________

A.she might be recognized

B.asking for help looked silly

C.she was normal and independent

D.being found blind was embarrassing小题2:After the girl got off the bus that evening, she_________.

A.began to run

B.hit a person as usual

C.hit a lamppost by accident

D.was caught by something小题3:At the request stop that evening, the girl___________.

A.stopped a big lorry

B.stopped the wrong bus

C.made no attempt to stop the bus

D.was not noticed by other people小题4:What was the problem with guessing at the sound to stop a bus? _________

A.Other vehicles also stopped there.

B.It was unreliable for making judgments.

C.More lorries than buses responded to the girl.

D.It took too much time for the girl to catch the bus