交换局的类型有（） A.端局 B.汇接局 C.长途局 D.关口局 E.综合局 F.国

下图是“地震波速度与地球内部圈层结构”示意图，其中E、F是地球内部的两个不连续界面，它们的名称依次是（  ）

A．莫霍界面、不连续界面

B．不连续界面、古登堡界面

C．莫霍界面、古登堡界面

D．古登堡界面、莫霍界面

抗氧化营养素有助于老年人自由基的消除，以下属于此类营养素的是( )。

A．硒

B．维生素B₁

C．β-胡萝卜素

D．半胱氨酸

E．核黄素

After a serious earthquake happened, a father left his wife safely at home and rushed to his son's school, only to find that the building where his son studied had collapsed and looked like a pancake.

He was shocked. He didn't know what he should do for a while, then he remembered the words he had said to his son, "No matter what happens, I'll always be there for you! "And tears began to fill his eyes. He started digging through the ruins (废墟).

　　As he was digging, other helpless parents and the firemen arrived and tried to pull him off the ruins, saying, "It's too late! They're all dead! There's nothing you can do! " To them he replied with one line, "Are you going to help me now? " And then he kept on digging.

　　No one helped, however. He went on alone because he needed to know for himself: "Is my boy alive or is he dead? " He dug for eight hours. . . 12 hours. . . 24 hours. . . 36 hours. . . then, in the 39th hour, he pulled back a rock and heard his son's words. He shouted his son's name, "ARMAND! " He heard back, "Dad!?! It's me, Dad! I told the other kids not to worry. I told them that if you were alive, you'd save me and when you saved me, they'd be saved. You promised, 'No matter what happens, I'll always be there for you!' You did it, Dad! "

"What's going on in there? How is it? " the father asked.

"There are 14 of us left out of 33, Dad. We're frightened, hungry, thirsty and thankful you're here. When t he building fell down, it made a triangle (三角) , and it saved us. "

"Come out, boy! "

"No, Dad! Let the other kids out first, because I know you'll get me! No matter what happens, I know you'll always be there for me! "

小题1:The underlined word "collapsed" probably means " ".

A．break down

B．shake away

C．stand by

D．fall into小题2:Who came to help the father when he was digging?

A．His wife.

B．Other parents.

C．The firemen.

D．No one.小题3:Other parents and the firemen wanted to pull him off the ruins because they thought .

A．he was mad

B．all the children had died in the earthquake

C．he was too dangerous to others

D．it was not his job to dig小题4:How many students were already dead when the father found them in the ruins?

A．Fourteen.

B．Thirty-three.

C．Forty-seven.

D．Nineteen.小题5:We can learn from the passage that .

A．it took the father one day to find his son and other students

B．his wife died in the earthquake

C．his son was the last one to come out of the ruins

D．the son didn't believe his father would come to save him

金融机构发现客户为外国政要的，风险等级划分为（）。

A.较高

B.高

C.一般

D.低

神经细胞电信号可以作远距离传导的条件是（）

A、产生电位波动

B、产生动作电位

C、产生局部电位

D、引起递质释放