问题 问答题

公园里培养了一些盆花,其中一些非常健康,也有一些缺乏营养,如图所示,

公园有一些化肥,以下是部分标签介绍:

(1)你认为花匠应该将上述三种肥料给哪类植物施肥(只填一个最合适的字母序号)?

①氮肥______     ②磷肥______     ③钾肥______

(2)硝酸镁(Mg(NO32)什么物理性质使它能作为肥料被利用?______

A.潮解      B.挥发性       C.可溶性

(3)花匠也注意到另一标签上的部分数据.如图,试根据标签上的含氮量计算:这包化肥中碳酸氢铵的质量是多少?

答案

(1)C的叶子发黄,缺乏氮元素,应施用氮肥;D根发育不良,叶片矮小,缺乏磷元素,应施用磷肥;B枝叶下垂,缺乏钾元素,应施用钾肥.

(2)硝酸镁易溶于水,易被植物吸收,故硝酸镁的可溶性使它能作为肥料被利用.

(3)由题意,这包化肥净重50kg,含氮量为16.8%,碳酸氢铵的相对分子质量为14+1×4+1+12+16×3=79,故这包化肥中碳酸氢铵的质量为50kg×16.8%÷

14
79
×100%=47.4kg.

故答案为:(1)C,D,B;(2)C;(3)47.4kg.

阅读理解

阅读理解。

     New rules and behavior standards (行为规范) for middle school students came out (颁布) in March.

Middle schools are going to use a new way to decide who the top students are. The best students won't only

have high marks. The following are some of the new rules.

     Tell the truth. Have you ever cheated (作弊) in an exam? Don't do it again! That's not something honest

students should do.

     Do more at school. Good students love animals and care for other people. April is Bird Loving Month in

China. Is your school doing anything to celebrate it? You should join! In that way, you can learn more about

animals and how to protect them.

     Be open to new ideas. Have you ever thought people could live on the moon? Maybe you'll find another

earth in space in the future. Everyone's new ideas are important.

     Protect yourself. Has a thief ever taken money from one of your classmates? Don't let it happen to you.

If you have to go back home late, you should let your parents know.

     Use the Internet carefully. The Internet can be very useful for your study. But some things on the Internet

aren't for kids, so try to look at the good web pages. You can use the web pages for fun or homework.

1. When did the new rules and behavior standards for middle school students come out?

    _________________________________________________________________________.

2. What should the best students do in an exam? 

    _________________________________________________________________________.

3. What should you do if you have to go back home late?

    _________________________________________________________________________.

4. What can the children use the good web pages for? 

    _________________________________________________________________________.

5. What is the right attitude (态度) to new ideas?

    _________________________________________________________________________.

单项选择题 B1型题