1.Semimetallic chemical element, chemical symbol B, atomic number 5.

1.半金学元素，学符号B，原子序数5。

2.Dyes come from plants or from chemicals.

2.染料是从植物或学物质中得来。

3.These chemicals are practically insoluble in water.

3.这些学物质几乎不溶于水。

4.As chemical reagent and corrodent of integrated plate.

4.作学试剂和集成电路电镀板消蚀剂。

5.The same water was reused after chemical treatment.

5.原来水经学处理之后再度使用。

6.Chemicals are used to keep the insects down.

6.学药品用于阻止昆虫滋生。

7.Have you studied the composition of the chemicals?

7.你研究这种药品成分了吗?

8.Choice having introduced the hammerhead and cleading chemical composition.

8.介绍了锤头和衬板学成分选择。

9.What are the chemical reaction characteristics of tropane alkaloids?

9.氢溴酸东莨菪碱鉴别原理是什么？

10.The chemical fertilizer should be well dug in.

10.学肥料应该均匀地混入土壤中。

11.Chemical modification including oxygenation, esterify, graft copolymerization and so on.

11.学改性主要有氧、交联、酯和接枝共聚。

12.The chemical must be salted out and allowed to dry.

12.必须把这种学物质加盐分离出来变干。

13.We put chemicals in test tubes in our chemistry class.

13.我们上学课时把学药品放进试管里。

14.The soil has been poisoned with chemical waste from the factory.

14.土壤被从工厂排出学废料污染了。

15.The heat brings about a chemical reaction, and oxygen is liberated.

15.热量引起学反应, 释放出氧气。

16.A catalyst is a substance which speeds up a chemical reaction.

16.催剂是一种能加速学反应物质。

17.The fission of the cell could be inhibited with certain chemicals.

17.细胞裂变可以通某些学药品加以抑制。

18.Chemicals in the body break our food down into useful substances.

18.人体中学元素把食物分解成有用物质。

19.Certain chemicals are easily absorbed into the bloodstream, while others are not.

19.某些学药品很容易溶于血液, 有些则不行。

20.The explosion of the chemical plant has poisoned many local residents.

20.那座工厂爆炸毒死了许多当地居民。