某一青年学生健康体检时，做心电图示心室率65次／分，P-R间期为0.26s，QRS-

在外照射防护措施中，常使用有机玻璃、铝、塑料等低原子序数作为屏蔽材料进行防护的射线是（）。

A.Χ射线

B.γ射线

C.β射线

D.中子

E.质子

在“探究加速度与力、质量的关系”实验中：

（1）某组同学用如图甲所示装置，采用控制变量的方法，来探究小车质量不变的情况下，小车的加速度与小车受到的力的关系。

该组同学由实验得出的数据，作出a-F图象，如图乙所示，那么该组同学实验中出现的问题可能是        

A．实验中摩擦力没有平衡

B．实验中摩擦力平衡过度

C．实验中绳子拉力方向没有跟平板平行

D．实验中小车质量发生变化

（2）下图所示是某同学通过实验得到的一条纸带，他在纸带上取A、B、C、D、E、F、G等7个计数点（每相邻两个计数点之间还有4个点没有画出），将毫米刻度尺放在纸带上。根据下图可知，打下E点时小车的速度为     m／s，小车的加速度为     m／s²。（计算结果均保留两位有效数字）

Ben walked quietly. He wanted to surprise the hunter. But then, what would he do?

Suddenly he heard a bird’s wings beating the dry grass. Ben moved quickly toward the sound.

He saw a colored head ... the head of a beautiful bird. The bird did not move until Ben came close. Then it tried to fly away, but one wing was broken.

Ben lifted the bird and held it close against his body. The bird fought to escape, but soon lay quietly in Ben’s arms.

Ben decided to take the bird home and fix its broken wings so that it could fly again.

He was almost out of the woods when he heard the hunter behind him.

“You just found that bird?” the hunter asked.

“Yes,” Ben answered.

“It is mine!”

Ben was afraid and tried to answer, but his mouth was too dry to speak. Nevertheless, he wetted his lips and said, “No.”

“I shot him and I say he is mine!”

“But he is not dead yet,” Ben answered, “and besides, anything on my land belongs to me.”

The hunter looked down at the little man and smiled. “Say, who are you?”

Ben’s voice shook with both fear and anger. “I own this land. There are signs everywhere that say, ‘No hunting’.”

“No need to get angry, mister,” the hunter said. “Control yourself.”

There was something threatening in the man’s cool quiet voice. And he had a gun. His arms were free and Ben’s were not.

The hunter stepped closer and said, “Give me that bird!”

Ben was white with anger. “No!” he answered. His eye glasses became wet and he had to look over the top of them to see the other man.

“Give me the bird and I will go away,” the hunter said.

“You get off my land,” Ben told him. “Get off right now...you do not belong here!”

The man’s face got red. “Mister,” he said, “I have been hunting here all my life. I grew up here.”

“That is a thing of the past,” Ben said. “I do not know who you are and I do not care. I own this place now and I am telling you to leave. You go back through the woods and get off my land!”

“Now look, mister,” the hunter said, “be reasonable.”

The hunter raised his gun.

A cold wind blew across Ben’s face. He looked into the hunter’s gray eyes. Ben was frightened. It was not too late, he thought. He could still give the bird to the hunter and return safely home...that would end this whole ugly business.

The bird struggled weakly and made a wild, strange noise.

Then Ben knew he could never give this bird to the hunter. This feeling gave Ben great strength, and he was no longer afraid.

“I will never let you kill this bird,” he said. “Get away from here. If you try to take this bird, I will fight...you have a gun and you are bigger, but that does not worry me. You will never get this bird...you will have to kill me first.”

The two men looked at each other. Ben’s fear returned. His knees began to shake and he felt sick. Yet he stood straight, wondering what would happen next.

They stood close to each other for a long time. The woods were strangely quiet. Then the hunter’s rough voice broke the silence.

“You are a fool.” And then to Ben’s surprise, he slowly walked away.

Ben watched until he was gone. His arms hurt, his body felt wet and cold.

67. Why did the hunter smile when saying “Say, who are you”?

A. He wanted to confirm Ben’s identity in a friendly way.

B. He was amused at Ben’s reply and interested in him.

C. He looked down on Ben and thought his reply ridiculous.

D. He meant to be friendly enough to get the bird from Ben.

68. What strengthened Ben’s determination never to give the bird to the hunter?

A. His strong dislike of the hunter.    B. His firm confidence in himself.

C. His ownership of this piece of land.   D. His concern and sympathy for the bird.

69. Why did the hunter remark that Ben was a fool at the end of the story?

A. Ben tried to protect a bird at all costs.

B. Ben pretended to be fearless although scared.

C. Ben stood close to him saying nothing for long.

D. Ben insisted on him leaving the land.

70. Which of the following best describes Ben’s state of mind in the incident?

A. Ben was willing to compromise.                B. Ben never thought of giving in.

C. Ben held out to the end.                                   D. Ben was sure about his victory.

燃气管道（）应设置在管道的上方，并能正确、明显地指示管道的走向和地下设施。

A、警示带

B、跟踪线

C、电子标示器

D、路面标志

资料6中引用了恩格斯的话：“个人隐私应受法律保护，但个人隐私甚至阴私与重要的公共利益——政治生活发生联系的时候，个人隐私就不是一般意义上的私事，而是属于政治的一部分，它不再受隐私权的保护，它应成为历史记载和新闻报道不可回避的内容。”你如何理解这句话
要求：准确、简明。不超过300字。