铁制品在通常情况下很易生锈，制造时往往在铁制品表面电镀一层铜_爱下问搜题

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问题选择题

铁制品在通常情况下很易生锈，制造时往往在铁制品表面电镀一层铜起防锈作用．下列说法正确的是（　　）

A．镀铜铁制品不可以在弱酸性条件下使用

B．镀铜铁制容器可盛硝酸银溶液

C．镀铜铁制品不易生锈的原因之一是使铁隔绝了空气

D．镀铜铁制品是一种合金

答案

A、铜与一般的酸不能发生化学反应，故镀铜的铁制品可以在弱酸性条件下使用，故A错误；

B、在金属活动性顺序中，铜在银的前面，铜能与硝酸银反应，故镀铜铁制品不能盛放硝酸银溶液，故B错误；

C、镀铜后铁与氧气隔绝，起到了防锈的作用，故C正确；

D、合金是指在一种金属中加热熔合其他金属或非金属形成的混合物，而镀铜没有将铁和铜熔合，故D错误；

故选C

完形填空

Six-year-old Brandon decided to make pancakes for his parents. He should first take the flour(面粉), so he   46  the cupboard and pulled out the heavy flour bag. He put some flour   47  the bowl with his hands, mixed in a cup of milk and added some sugar.
Soon Brandon was 48 flour and getting frustrated, He wanted this to be   49  for Mum and Dad, but it was getting very bad. He didn't know what to do   50 .
Suddenly he saw his cat near the bowl and went to push it away, but he   51  the egg box to the floor. He tried to   52  but slipped(滑倒) on the eggs, getting his clothes   53 . Just then, he saw his dad standing at the door.
Brandon's eyes were full of tears. He was   54  his dad would beat him, but his father didn't.   55 , he picked up his crying son and kissed him.
That's what we sometimes face in   56 . We try to do something good, but it turns into a mess. Sometimes we just   57  there in tears because we can't think of anything else to do. Hopefully, that's   58  someone close to us picks us up, loves us and forgives us. But we can't    59  trying to "make pancakes" for "Dad" or for others. Sooner or later we'll get it   60 , and then they'll be glad we tried.

B．covered with

A．something good	B．anything bad
C．everything bad	D．nothing good

判断题

只要给生物空气和阳光，生物就能成活。[ ]