题干

某同学利用如图所示装置测定空气中氧气的含量,红磷燃烧后恢复到室温时,打开弹簧夹发现进入集气瓶中的水的体积远远大于原空气体积的
1
5
。请你推测造成这一现象的原因可能是(   )

A:实验前没有夹紧弹簧夹

B:实验装置可能漏气

C:实验中所取的红磷过量

D:实验中所取的红磷不足

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答案(点此获取答案解析)

A

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Jack had an unusual experience last night. He is sharing it with his friends. Ken and May.

Ken: What were you doing, Jack What did you see

Jack: It was half past nine last night and I was getting ready for bed. I heard some strange noise outside while I was brushing my teeth. I wondered what was happening and I went to the window and looked out. To my surprise, I saw a bright yellow green light in the sky.

May: Maybe the light you saw was a UFO! Or a ghost! A few years ago, an American man saw a flying saucer while he was driving along a road. He also saw some strange yellow light. You have heard about it, haven't you

Ken: Don't be imaginative, May. Jack didn't see anything, or anybody. It wasn't a ghost. It was probably a plane, or a shooting star .Perhaps Jack just made a horrible dream!

Jack: I am very serious .I did see something. The light disappeared and then suddenly some “tiny people” were standing in the garden .There were four of them .Two of them ate some flowers in the garden .It was always stretching out its arms.

Ken: Oh, come on, Jack. I really doubt what you have said.

Jack: I am not joking! One of the people was looking at me through the window.

May: Really What did it look like Were you frightened

Jack: Its whole body was green. It had no ears and nose. Its hands were huge. Its eyes were very big and resembled eggs. It started at me and I could hardly move.

Ken: What happened then ?

Jack: I was able to move eventually. I ran and got my camera immediately.

May: And......

Jack: I didn't have a film.

May: Oh no!