负压吸宫术局麻镇痛方法不包括（） A.地西泮宫颈注射 B.丙泊酚宫旁阻滞麻醉 C.1

可不使蛋白质变性的是

A．有机溶剂

B．重金属盐

C．盐析

D．加热震荡

E．强酸、强碱

铜制的钥匙坯片(配钥匙用)

阅读理解。

     "How can I learn English well?" This is a question many students ask. In my opinion, the most effective

way is to learn lessons by heart. If you can recite the text and write it out, you've learned it fairly well. And

if you can retell, in your own words, what the lesson is about, you're a very successful learner indeed. Your

English will be quite perfect. This is a difficult task. However, if you try to learn by heart only part of each

lesson, you'll find it not so hard as you might have expected.

     Learning this way, you will make rapid progress. Of course, writing is also necessary. It helps you a lot

on your way to success in English.

     Equally important is to feel the language. You should be able to laugh at jokes and be shocked at bad news.

When using English, try to forget your mother tongue. Instead of helping you, your own language gets in your

way. So, never try to see English through translation.

1. In the writer's opinion, the most effective way in learning English is _____.

A. to practise speaking, writing and feeling it

B. to memorize the English words and grammar

C. to translate everything into your own language

D. to forget your own native language

2. "Instead of helping you, your own language gets in your way." This sentence means that memorizing your

    own language can _____.

A. stop you mastering (having a good command of) English

B. help you to study English well

C. make English easy to learn

D. help you notice mistakes

3. "To feel the language" here means _____.

A. to get the knowledge of English by touching

B. to read and write English

C. to experience the rich meaning of the language

D. to translate English into your own by imagining

某同学应用如图所示的方法研究物质的性质，其中气体a的主要成分是氯气，杂质是空气和水蒸气。

回答下列问题：

(1)该项研究（实验）的主要目的是______________________

(2)浓硫酸的作用是_________________ 与研究目的直接相关的实验现象是_______________

(3)从物质性质的方面来看，这样的实验设计存在着事故隐患，事故表现是______________ 请在图中D框中以图的形式表明克服事故隐患的措施。

氧化氮压缩机的联轴器需要进行（）校正。

A.低速动平衡

B.高速动平衡

C.中速动平衡

D.拉伸