试述高层结构的主要结构形式及特点？

投保人或者被保险人对过去或现在某一特定事实的存在或不存在的保证属于( )。

A．明示保证

B．默示保证

C．确认保证

D．承诺保证

At Harton College-an English boarding school（寄宿制学校）for boys-there are many rules.Fifteen-year-old Bob Sanders often breaks them.

The boys can go into the town in the afternoon after class. But they must return to the school at six o’clock. One afternoon Bob walked to the town. He looked at the shops and then went to the cinema. After the film, he looked at his watch. It was after eight o’clock. He was a little worried . He walked back to Harton College as fast as possible.

When he arrived, he ran quickly to the main entrance（主要入口）.It was locked. He went round the school buiding to another door. That one was locked too. He looked up at the window of his dormitory（宿舍）.It was on the third floor. The window was open. But it was quite dark and he could not climb up the wall easily. Then he saw another open window on the ground floor. It was the window of the headmaster’s study（书房）.

He looked into the room-no one was there. Bob quickly climbed on to the window and jumped into the room. Just then he heard a noise. Then someone turned on a light in the corridor（走郎）.Bob looked around and then hid under the sofa. One minute later, Mr Mannering the headmaster, came in. He turned on the light on his desk, and sat down on the sofa（沙发）.Then he opened a book and began to read.

Bob lay under the sofa as quietly as possible. He couldn’t move. The floor was cold and uncomfortable. He looked at the headmaster’s shoes and socks for an hour.

“Why doesn’t he get up and go to bed?”Bob thought.

Mr. Mannering read his book for another hour.Finally, the headmaster closed his book and stood up. He put the book on a shelf and walked towards the door.

“Thank God he didn’t find me under the sofa,”thought Bob.

Then Mr. Mannering stopped and spoke towards the sofa.

“Would you turn off the light when you leave?”

He said, and left the study.

57．Bob returned to the school more than two hours late because_______.

A．he enjoyed himself too much  B．he did not catch the bus

C．he hated the rules     D．he ran into an old friend

58．The main entrance was_______.

A．too high   B．open  C．shut   D．slightly open

59．Bob didn’t go to his dormitory because_______.

A．the gate was locked  B．the window was shut

C．it was quite dark      D．the wall was too high for him to climb up

60．Bob actually went into the headmaster’s_______.

A．dormitory        B．private（私人的）office

C．kitchen            D．bedroom

控制水痘传播的主要措施有哪些（）

A.隔离水痘病人至皮疹完全结痂或出疹后7天

B.易感人群积极使用抗病毒药物

C.消毒水痘病人的分泌物污染物品

D.必要时向易感人群提供被动或主动免疫预防感染

E.带状疱疹病人也应该严密隔离

审美起源诸理论的意义与不足是什么？

在担保的问题上，主要有两个方面的问题要重点考虑，一是法律方面，二是( )方面。

A．经济
B．政治
C．风险
D．收益