静止流体内部某处的压强大小随着其深度的增加而（）。 A.减小 B.不变 C.增加 D

阅读短文，判断正(T)误(F)。 

      I have a five-year-old pet dog. It is white with small black spots (斑点). Whenever (每当) it sees me, it 

always barks (咬，叫) with its tail shaking (摇). I love my pet dog, because it keeps me happy whenever I'm 

lonely (寂寞).

( ) 1. My pet dog is four-year-old.  

( ) 2. The pet dog is white with small black spots. 

( ) 3. My pet dog doesn't like me. 

( ) 4. The pet dog always barks when it sees me.

( ) 5. When I'm lonely, the pet dog always keeps me happy. 

动物体的结构层次依次是（　　）

A．细胞→组织→系统→动物体

B．细胞→组织→系统→动物体

C．细胞→组织→动物体

D．细胞→组织→器官→系统→动物体

根据句意及首字母提示在横线处填上恰当的单词，使句子意思完整，语法正确。

1. There are three s_______in my study.  There are many kinds of books on them.

2. The dictionary is h_______to us.  I think you should buy it.

3. I don't want to take part in Mary's party, so I_______her invitation.

4. My old shoes h_______my foot, so I've to buy a new pair.

5. She c_______her face with her hands just now.  She seemed to have cried.

6. My mother always t_______us like children.

7. I think you should put a f________book near your bed. If you have any problems, you can read it.

8. He is a good and famous writer.  A new book came o   _____last week again,

9. If you cut yourself by accident, you should p_______the cut hard.

10. If you fell d________by accident and wasn't able to move, you should call the hospital first.

下列物质的应用错误的是(    )

A．干冰用于人工降雨

B．活性炭用于净水

C．氧气用于食品保鲜

D．氮气用于超导实验

某施工企业现承包了某11层商住楼工程施工，其屋面梁定额用C20每立方米用425号水泥245公斤，共浇筑了23.6立方米，实际耗用水泥5024公斤。请依据上述背景资料完成下题

该工程屋面梁C20混凝土的水泥材料节约率为（）。

A、13.1%

B、12.8%

C、11.9%

D、12.3%