在炼钢过程中需要用抽样的方法对产品的技术指标及时进行检测．现

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问题问答题

在炼钢过程中需要用抽样的方法对产品的技术指标及时进行检测．现取12 g样品，在足量的氧气中充分燃烧，收集到0.11 g二氧化碳．计算此样品中碳的质量分数，并判断该样品是否达到钢的要求．______．

答案

0.11 g二氧化碳中碳元素的质量为：0.11 g×

×100%=0.03g，

样品中碳元素的质量分数为：

0.03g

12g

×100%=0.25%，

此样品达到钢的要求．

单项选择题 A1型题

影响经皮吸收的主要因素中，不包括（）

A.化学物质分子量的大小

B.化学物质的脂／水分配系数

C.皮肤血流和组织液流动的速度

D.皮肤完整性和通透性

E.皮肤菌群情况

填空题

用所给词的正确形式填空。

1. She said she (watch) TV at this time yesterday.

2. I think I________(stay) at home tomorrow.

3. He invited her ________(dance)for me.

4. My sister would like________ (be) a movie star.

5. I'm against ________ (stay) here. We must go now.

6. I think there will be ________ (little) pollution in ten years.

7. If it (not rain), we'll go to the park tomorrow.

8. While the alien was _________ (visit) the museum, the boy called the TV station.

9. In English, I'm ________ (good) at reading than listening.

10. For many young people, becoming a ________ (profession) athlete seems like a dream job.