chemical 四级考研

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

半金属的元素，符号B，原子序数5。

Dyes come from plants or from chemicals.

染料是从植物物质中得来的。

The behavio(u)r of the chemicals was unexpected.

这些药品的变是出人意料的。

These chemicals are practically insoluble in water.

这些物质几乎不溶于水。

Chemically treated hair can become dry and brittle.

经过处理的头发会变得焦脆。

Hydrogen combines chemically with oxygen to form water.

氢和氧合成为水。

Chemicals are used to keep the insects down.

药品用于阻止昆虫滋生。

Have you studied the composition of the chemicals?

你研究过这种药品的成分了吗?

As chemical reagent and corrodent of integrated plate.

作试剂和集成电路电镀板的消蚀剂。

The same water was reused after chemical treatment.

原来的水经过处理之后再度使用。

The chemical fertilizer should be well dug in.

肥料应该均匀地混入土壤中。

What are the chemical reaction characteristics of tropane alkaloids?

氢溴酸东莨菪碱的鉴别原理是什么？

Choice having introduced the hammerhead and cleading chemical composition.

介绍了锤头和衬板成分的选择。

To study chemical constituents of hypogeal part from Limonium bicolor.

研究二色补血草地下部分成分。

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

改性主要有氧、交联、酯和接枝共聚。

The chemical must be salted out and allowed to dry.

必须把这种物质加盐分离出来并让它变干。

We put chemicals in test tubes in our chemistry class.

我们课时把药品放进试管里。

Certain chemicals can induce undesirable changes in the nervous system.

有些物质能在神经系统中引起不良变。

Chemical analysis of the lymphocele fluid allows differentiation from a urinoma.

由于压迫到肾脏，大的淋巴管瘤往往造成血清肌酐升。

The microorgan-isms employed include mainly chemical conversion bacteria,phototropic bacteria and alga.

转细菌、向光性细菌和藻类。