在邻近或交叉500kV交流带电电力线处作业的安全距离为（）m。 A.3 B.4 C.

男性患者，40岁，咳嗽伴呼吸困难，查体：右下肺叩诊浊音，右下肺呼吸音消失，该患者可能为

A．胸腔积液

B．自发性气胸

C．心包炎

D．支气管扩张

E．肺气肿

修建性详细规划是以城市总体规划或分区规划为依据，确定建设地区的土地使用性质和使用强度的控制指标、道路和工程管线控制性位置以及空间环境控制的规划要求。()

华东理工大学成立于（）年。

A.1950

B.1960

C.1952

D.1951

TEXT B
One of the mysteries of nature is animal communication. Creatures of the sea move through their liquid element without any hearable sound. Yet they are able to sense the silent passing or attack of others of their kind. This is because bodies moving in water create a pressure wave, something like a gust of wind produced by a passing automobile. A narrow sensor system running along each side of the shark, from eye to tail, receives and interprets these pressure waves. I have seen sharks appear swiftly, obviously drawn by the motion of a diver’s hands, which had sent out p waves.
One might think it impossible to distinguish odors in water. Yet sharks, surprisingly, are able to follow a scent across miles of ocean and arrive at its exact source. A diver who spears a fish and attaches its bloody body to his belt, and then goes on with the hunt, becomes a natural prey to the shark. I have seen sharks follow a scent exactly like the dogs of a hunting pack. It is no wonder that the Greeks gave them the name "hounds of the sea."
One of the most widely believed--and dangerous--legends about the shark is that he has poor eyesight. On the contrary, the shark is well equipped to see at a distance and to distinguish among forms. This fact was proved to me one day when I went into the water off the coast of Africa. I sighted a shark at some distance from me as I was floating at a very shallow depth. Since I was making no movement, the sound of bubbles from my diving apparatus would be confused with the light splashing of the water on a rock. I turned my eyes away for a few seconds, to study the design of a giant ray just beneath me. I am not sure now whether it was simple instinct or a feeling of movement, but I turned back abruptly toward the location of the shark. And, immediately, every muscle of my body tensed. He was no more than 30 feet away, launched toward me as hard and swift as a missile.
The sight of a shark coming at you head-on is strange. Obviously it is from this angle that he seems most frightening--the very symbol of evil, with the half-opened mouth and the three regularly spaced fins (鳍). When the shark had approached to within two feet of the rubber fins I had thrown at him as a gesture of self-defense, he turned suddenly and swam back toward the depths. There had been no sound, no scent. It appears certain that sight alone was responsible for this approach.

The author escaped from the attack of the shark by ______.

A．turning around suddenly

B．screaming

C．swimming back to the shore

D．throwing rubber fins at him

地方政府职能扩大的表现、原因及扩大后面临的困境表现？