三相对称负载作三角形连接，接入三相电压380V，每相负载电阻为6Ω，感抗为8Ω，求相

下列判断正确的是 [ ]

 A．纯碱属于碱 

 B．不锈钢属于纯净物

 C．干冰属于氧化物

 D．C₆₀属于化合物

能降低神经的应激功能，对感觉和运动神经均能起抑制作用的波型为（）。

A、密波

B、疏波

C、疏密波

D、断续波

E、锯齿波

After the terrible car accident, the whole world had been completely dark and quiet for Robert Edwards for almost ten years, for he became both blind and deaf after the doctor had saved him. The loss of sight and hearing threw him into such a sorrow that he tried a few times to put an end to his life. His family especially his wife did their best to tend and comfort him. By and by he finally regained the courage to live on.

On a hot summer afternoon he was taking a walk with a stick near his house when a thunderstorm started all at once. He stood under a large tree in order not to get himself wet. Unfortunately he was struck down to the ground by a lightning. The witnesses thought him dead but he woke up some 20 minutes later lying face down in muddy water below the tree. He felt that he was trembling badly, but when he opened his eyes ,he didn’t dare to believe that he saw a plough (梨子) lying near the wall. When Mrs Edwards came running up to him, she shouted their neighbours for help. And he saw her and heard her voice for the first time in nearly ten years.

The news of Robert’s regaining his sight and hearing quickly spread in his area. And many doctors came to prove the truth of the news. Most of them said that he gained sight and hearing again obviously from the knock of lightning; none of them could give convincing reasons,

小题1:

小题2:

小题3:

小题4: How did Edwards get his sight and hearing once more according to the doctor?

A．He regained them from head injury when he fell from a tree.

B．His wife’s first visit after almost ten years made him so happy that he regained them.

C．The lightning took the feeling from his legs and gave the senses of sight and hearing to his head.

D．The blow that caused him blind and deaf was very severe, so it took another severe blow to regain them.

一家三口人，三年前三人年龄之和是70，且当时妈妈的年龄是儿子的5倍，妈妈的年龄比爸爸小4岁，爸爸今年多少岁（）

A．36

B．34

C．40

D．37

旅客因误售、误购、误乘或坐过了站需送回时，车站应在车票背面注明（）并加盖站名戳，指定最近列车免费送回。

A.“误售”

B.“误购”

C.“误乘”

D.铁路责任