沿着圆锥底面直径和高把圆锥切成两部分，切面是一个三角形．______．（判断对错

设N_A表示阿伏加德罗常数的值，下列叙述中正确的是 [ ]

A．2．4g金属镁变为镁离子时失去的电子数为0．1 N_A

B．1．8g的NH₄⁺离子中含有的电子数为0．1N_A

C．11．2 L氧气所含的原子数为N_A

D．常温常压下，48gO₃和O₂的混合气体中含有的氧原子数为3N_A

It was in New Zealand        Elizabeth first met Mr. Smith.  [ ]

A. that      

B. how

C. which      

D. when

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项.选项中有两项为多余选项.

     What is your favourite colour? Do you like yellow, orange, red?  1  . Do you prefer greys and blues?

Then you are probably quiet, shy, and you would rather follow than lead. You tend to be pessimist. At

least, this is what psychologists tell us, and they should know, because they have been seriously studying

the meaning of colour preference, as well as the effect that colours have on human beings.  2  . If you

happen to love brown, you did so, as soon as you opened your eyes, or at least as soon as you could

see clearly. 

  3  . A yellow room makes most people feel more cheerful and more relaxed than a dark green one;

and a red dress brings warmth and cheer to the saddest winter day.  4  . A black bridge over the

Thames River, near London, used to be the scene of more suicides(自杀) than any other bridge in

the area - until it was repainted green. The number of suicide attempts immediately fell sharply.

Perhaps it would have fallen even more if the bridge had been done in pink or baby blue.

  5  . It is an established fact that factory workers work better, harder, and have fewer accidents

when their machines are painted orange rather than black or grey.

A. On the other hand, black is depressing.

B. They tell us, among other facts, that we do not choose our favourite colour as grow up we are born

with our preference.

C. The rooms are painted in different colours as you like.

D. If you do, you must be an optimist, a leader, an active person who enjoys life, people and excitement.

E. Light and bright colours make people not only happier but more effective.

F. Life is like a picture or a poem, full of different colours.

G. Colours do influence our moods---there is no doubt about it.

( )是指废弃和闲置的土地经复垦恢复到可利用状态的区域。

A．土地恢复区
B．土地整理区
C．土地复垦区
D．土地综合治理区

往复式压缩机试车过程中，应检查是否有（）。

A、部件松动

B、异常振动

C、超温现象

D、异音