问题 选择题

保持物质化学性质的微粒是(  )

A.N

B.H

C.2O

D.CO2

答案

A、表示氮原子,由于构成氮气的微粒是氮分子,所以保持氮气化学性质的最小粒子是氮分子,故A错;

B、表示氢原子,由于构成氢气的微粒是氢分子,所以保持氢气化学性质的最小粒子是氢分子,故B错;

C、表示2个氧原子,由于构成氧气的微粒是氧分子,所以保持氧气化学性质的最小粒子是氧分子,故C错;

D、表示二氧化碳分子,保持二氧化碳化学性质的是二氧化碳分子,故D正确.

故选D.

完形填空

It was near Christmas during my first semester teaching a new school. I love my small special class more than any group I had taught in the past. They were hungry for knowledge and I was enjoying teaching.

Other teachers had told me that our children were from poor families and not to expect any child to bring a Christmas gift. In fact, I wasn’t expecting any gifts.

Imagine my surprise when every child brought me a gift on the day before our holiday break. First, I got a much-loved stuffed monkey from a shy girl. I was told, “He is my favorite, but I love you and I want him to be with you, Miss Taylor” How thrilled I was!

Next came a new set of Christmas tree lights that was “missing” from a mother's cupboard.

Finally, I came to one little boy’s gift which I had never received. It was an old, dirty and broken Christmas story book. Just then I wanted to express my happiness, I was interrupted(打断)by the giver, “And see, it is new! It still has the price tag.”        "

When other children laughed at him, I stopped them and said, “Oh, books are good in that way. The story is always new if you have not read it before. Now, Let’s share one together.” Everyone listened quietly as I read the most wonderful Christmas story of my life.

I still keep those Christmas gifts, They always remind me of my lovely kids.

小题1:Why did the teacher like her small special class?

小题2: When did the children bring their teacher gifts?

小题3:Who sent a stuffed monkey to the teacher?

小题4:Was the Christmas story, book new?

小题5:How did the teacher feel when she got the presents?

选择题