与筒体及法兰等连接而可拆的称为端盖。

喝入甲醇，吸入甲醇蒸气或甲醇侵入皮肤都可能引起甲醇中毒。

A Nice Clean Plate

It’s Saturday evening. Bruce is having a birthday party. There are a lot of children at the party. They play together for an hour. Then Bruce’s mother gives them some food. But she forgets to give Sam any.

Sam feels wronged(委屈) but then he remembers his mother’s words, “Be polite.(礼貌). Don’t ask for food.” So he waits for a few minutes, then he holds his plate up over his head and says loudly, “ Does anyone want a nice clean plate?”

小题1:What day is it?

A．Sunday

B．Saturday

C．Monday

D．Friday小题2:What are the children doing in the afternoon? They are ___.

A．reading

B．singing

C．playing

D．dancing小题3:They play for ___.

A．an hour

B．ten minutes

C．half an hour

D．twenty minutes小题4:Who gives them some food?

A．Bruce’s father

B．Bruce’s uncle

C．Bruce

D．Bruce’s mother小题5:Sam’s mother tells him not to ___.

A．play in the street

B．ask for food

C．play with girls

D．swim in the river

镍氢电池比碳锌或碱性电池有更大的输出电流，更适合用于高耗电产品。镍氢电池的总反应式是。下列叙述错误的是

A．电池充电时，氢元素被还原

B．电池放电时，镍元素被氧化

C．电池放电时，氢气在负极反应

D．电池放电时，电池负极周围溶液的碱性减弱

生产性粉尘有以下致病作用，除外（）。

A、局部刺激、感染

B、中毒、致癌

C、变态反应、光感作用

D、致纤维化作用

E、麻醉作用