问题 填空题

相同质量的CO2和SO2中,含氧量之比为______.若使CO2和SO2中含氧量相同,则这两种物质的质量比为______.

答案

相同质量的二氧化碳和二氧化硫中含氧量之比为

16×2
44
:1×
16×2
64
=16:11

二氧化碳和二氧化硫中含氧量相同时两物质的质量比为

1
16×2
44
1
16×2
64
=11:16

故答案为:16:11,11:16.

阅读理解

阅读理解。

     A good way to pass an exam is to work hard every day in the year. You may not do well in the exam if

you are lazy for most of the year and then work hard for a few days before the exam. If you are taking an

English exam, don't only learn rules of grammar. Try to read stories in English and speak English when you

can. A few days before the exam, you should start going to bed early, don't stay up late at studying and

learning things. Before you start the exam. read carefully the question paper. Try to understand the meaning

of each question before you pick up your pen to write. When you have at last finished your exam, read over

your answers, find out any mistakes which you see and make sure that you haven't lost anything out.

1. The good way to pass an exam is ________.

A. to work hard at all lessons all the year round

B. to work hard only before the exam

C. to stay up late before the exam

D. to spend all the time remembering rules of grammar

2. Before you start the exam, you should ________.

A. speak loudly

B. learn rules of grammar

C. read carefully the question paper

D. revise your lessons

3. You should _______ your answers before the exam paper is handed in.

A. copy

B. write

C. read

D. cheek

4. Before you pick up your pen to write, you should ________.

A. copy the sentences

B. look up the words in the dictionary

C. revise your book

D. understand the question on the paper

5. Which topic (题目) is the best?

A. Read More Books

B. A Good Way to Pass an Exam Study

C. Do Exercises

D. Hard at Your Lessons

问答题 简答题