认真细致的观察和分析实验现象，有助于获得化学知识并学会科学探究的方法．以下分析你认为合理的是（ ）
A．海水晒盐就是利用阳光和风力使水分蒸发得到粗盐
B．某物质在氧气中完全燃烧，生成了氧化物，可证明该物质一定是单质
C．把燃着的木条伸入集气瓶中，火焰熄灭，可证明该气体一定是二氧化碳
D．两种物质完全反应后生成了盐和水，可证明该反应一定是中和反应
答案：A
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| "How can I learn English well?" "This is a __1__ many students may ask. In my opinion, the most effective (有效的) __2__ is to learn lessons by heart. If you can recite the text and write it out, you will learn it pretty well. And if you can tell __3__ your own words about __4__ the lesson says, you are 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 __5__ you might have thought. Learn this way, and you will __6__ fast progress. Of course, writing is also necessary. It helps you a lot on your way to __7__ in English studies. It's equally (同样地) important to feel the language. You should laugh at Englsih jokes and be __8__ at bad news. When using English, try to __9__ your mother tongue (母语). __10__ helping you, your own language gets in your way. So, never try to learn English through putting every word into Chinese. | |||
| ( )1. A. problem ( )2. A. time ( )3. A. with ( )4. A. which ( )5. A. than ( )6. A. do ( )7. A. success ( )8. A. happy ( )9. A. leave ( )10. A. Instead of | B. puzzle B. way B. by B. what B. like B. make B. challenge B. happily B. forget B. Instead | C. question C. road C. of C. how C. so C. learn C. difference C. sad C. remember C. Besides | D. challenge D. place D. in D. when D. as D. develop D. importance D. sadly D. realize D. Except for |