阅读理解，选择正确答案。

      My name is Liu Ming. I have a new schoolbag. It's on the desk. It's pink and white. There are eight books

in it. An English book, a Chinese book, a math book, three notebooks and two story-books. My schoolbag is

beautiful. I like it.

1. Where is Liu Ming's schoolbag?

A. Under the desk.

B. On the desk.

2. What colour is the schoolbag?

A. It's pink and black.

B. It's pink and white.

3. How many books are there in the schoolbag? 

A. Three.

B. Eight.

4. How many notebooks does Liu Ming have?

A. Three.

B. Eight.

在破碎筛分系统中，筛子选择至关重要，最好选用长、宽比为（）。

A、≧1

B、≧2

C、≧3