电场中根据电力线的性质指出:电力线的方向是由()。
A.正电荷起到负电荷止
B.负电荷起到正电荷止
C.N极起到S极止
参考答案:A
第二节语法填空(共10小题;每小题1.5分,满分15分)
阅读下面短文,根据上下文填入适当的词语,或使用括号中的词语的适当形式填空。
Marty has a muscle disease that sometimes makes him very weak and he can’t run or climb stairs as quickly as other people. The doctors don’t know___31___(exact)what is wrong with him. 32 (luck),Marty has learned to adapt to his disability. He used to dream 33__
one day being a famous football player and 34 (represent) his country in the World Cup.
He doesn’t look any different from 35 people. So sometimes kids laugh at him 36
he gets out of breath. Life is much 37 (easy) at high school than it was at primary school.
Even when he is made fun of, he does not get 38 (annoy).Disabled 39 he is, Marty has become stronger and more independent. He suggests that we normal people should give the disabled 40 (encourage) rather than laugh at them.
有点浇口的模具脱模机构中,限位零件拉杆的作用是()
A、使塑料制件脱模
B、使塑料制件与点浇口断开
C、动、定模分型
D、限制开模行程