由下列水泥拌合成的砂浆，耐磨性最好的是（）。 A.硅酸盐水泥 B.粉煤灰水泥 C.矿

阅读理解。

     It was Sports Day at School. There were many races. Lots of parents were watching the children.

    There was a large crowd of people. Some girls were talking about the races. They were talking about who

win the 100-metre race. Jone heard what the girls were talking about. He was eating a banana. He said,"I shall

win the race! I am the fastest runner!" When he finished his banana, he throw the skin on the ground, and left.

     Mr Sun shouted,"100-metre race for boys!" Jone and the other boys went to the start of the race. The boys were ready now. Mr Sun held up a gun. He fired the gun into the air, and the race started. Jone ran very fast.

He was near the end of the race. He was smiling, but suddenly, he put one foot on the banana skin.He slipped

and fell down. He fell in front of Sam. Sam fell down, too. Then Ben fell down. Paul was behind them. He

passed them carefully and ran on. At last Paul won the race.

     "Congratulations, Paul," said Miss Smith. "You are the winner."

1. Some girls were talking about the ________.

A. 100-metre race

B. 200-metre race

C. 800-metre race

D. 1000-metre race

2. Jone threw the skin on the ground when he finished the ________.

A. orange

B. banana

C. apple

D. pear

3. Who won the race finally?

A. Sam

B. Jone

C. Ben

D. Paul

4. How many people fell down?

A. One

B. Two

C. Three

D. Four

5. What do you think the passage most probably is?

A. A newspaper report

B. A novel

C. A student's composition

D. A TV play

关于受迫振动的下列说法中正确的是(   )

A．受迫振动的频率等于物体的固有频率

B．受迫振动的频率与物体的固有频率无关

C．驱动力越大，物体做受迫振动的频率越大

D．驱动力的频率越接近物体的固有频率，受迫振动的振幅增大

．下列有关描述所对应的化学用语正确的是

A．Na₂S的水解：S^2－+2H₂OH₂S+2OH^－

B．碳酸的电离方程式：H₂CO₃2H⁺+CO₃^2－

C．右图反应开始时的离子方程式：Cu＋2H⁺Cu²⁺＋H₂↑

D．氢氧碱性燃料电池的负极反应式：H₂－2e^－＝2H⁺

社会环境对人类健康的影响日益受到重视，它相对于自然环境又被称为（）

A.机体外环境

B.机体内环境

C.物质环境

D.非物质环境

E.其它

4字征阳性提示（）

A．先天性髋关节脱位

B．骶髂关节病变

C．腰椎间盘突出症

D．梨状肌综合征

E．交叉韧带病