在建工程（含脚手架）的周边与10KV外电架空线路边线之间的最小安全操作距离应是（）。

给下列加粗字注音

慕义强仁（　）矧（　）郁（　）吾恶知（　）

阅读理解。

    In 2000, at the age of 56, Jeff was going to take a difficult and dangerous journey (旅行) in the Arctic

(北极地区). He was planning to walk to the North Pole all by himself, pulling his food, tent (帐篷) and

other things behind him in two sledges (雪橇). Because the Arctic is covered with ice and water, he would

sometimes have to sit on his sledges and use them like a boat!

    Before he started his journey, to make himself stronger, Jeff spent 2 years practicing running and took

part in many boat races. He had also traveled in the Arctic for 28 years. All of this was good for him. But

there was still trouble.

    Jeff was seven days into his journey in the Arctic. It was dark and terribly cold (-35℃). In face of this

terribly low temperature, he had made good progress across the ice. Suddenly, the ice broke and one of his

sledges fell into the sea. Jeff needed to get it back, so he had to put his hand into the ice-covered water.

    Once he had got the sledge back, Jeff put up his tent, lit a fire and tried to warm up his cold hand. It was

no help-his hand was seriously hurt as it had been in the cold for so long. He radioed for help, and an airplane

was sent to save him. Finally, he arrived at a hospital in Canada. The doctors there said he hurt his left hand

in the icy water. They saved his hand and advised him not to travel to the North Pole alone any more.

    But Jeff was an explorer and nobody could change his mind. It would be yet another long and difficult

challenge for Jeff soon.

1. Jeff started to travel in the Arctic in           .

A. 1970

B. 1972

C. 1998

D. 2000

2. Jeff            for 2 years before his journey.

A. made a special tent

B. practiced running

C. had medical checks

D. took a long walk

3. After one of his sledges fell into the sea, what did Jeff do first?

A. He put his hand into water.

B. He lit a fire near the tent.

C. He warmed up his hand.

D. He put up his tent.

4. What can we infer (推断) from the last sentence of the article?

A. Jeff would practice more for the next journey.

B. Jeff would explore another part of the Arctic.

C. Jeff would try his best to realize his wish.

D. Jeff would refuse to take any advice.

目前我国70%以上的坡耕地都集中在[ ]

A．华北地区

B．中原地带

C．西北地区

D．西南地区

下列关于超声成像的优点描述不正确的是（）。

A.能够方便动态实时观察

B.能够很好地同时显示多个器官或结构的整体关系

C.价格相对低廉

D.能很好地检测心血管等运动器官的重要生理功能

E.无创伤、无电离辐射

高浊度水的沉淀处理工艺流程通常分为哪几类？