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单项选择题

根据混凝土拌合物的稠度确定混凝土成型方法，不大于某一坍落度的混凝土宜振动压实；大于该坍落度的宜采用捣棒人工捣实。此坍落度值为（）。

A.30mm
B.50mm
C.70mm
D.90mm
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单项选择题
"...She was married to an officer in India,long ago India;and she had a life of physical adventure(冒险)as exciting as her poetry.Her husband could cross rivers using crocodiles(鳄鱼)as stepping stones.He died when she was only 39.Unwilling to exist without him,she took her life,leaving a son in England."
I stared at the paper,21?reading,couldn′t help thinking.
Crocodiles are lazy animals as a rule,but they can move like lightening when they want to.And they don′t mind hurrying?22?they′re hungry.There used to be lots in Indian rivers,living on fish mostly;but what′s a little fish for a fifteen-foot crocodile？They ate people,fisherman or anyone else delicious enough to get too near;women doing the?23,or children playing at the water′s
24.A hungry crocodile′s mouth?25?over a meal with a sound like a gunshot.A big fellow can?26?in a man in two bites(咬)。
That woman′s husband crossed rivers?27?from one crocodile′s back to the next.I believe it.It had to be done quickly before the creature could see what was happening.It wasn′t28?a brave,active man;and no doubt he improved with practice.He could never look?29while crossing.
The wife used to watch him--I felt sure of that.She lived?30?the adventure,the?31?excitement of it all.Their real life was with tigers,snakes...It′s no wonder she wrote?32poetry.
Then he died.I imagined how she felt.Was there another man?33?him in India,in the world?She was still young,hardly a sitting-room widow(寡妇)."I must?34,too."she said to herself.So she did what she felt she had to do.A?35?probably,to her head.
But her young son,their son?Was her love for him nothing compared to her husband?Well,what do you think?
第21题答案是
A.started
B.began
C.finished
D.stopped
单项选择题
为保持病室内空气清新,一般每天通风2次,每次的时间是()
A、10分钟
B、20分钟
C、30分钟
D、60分钟
E、90分钟
单项选择题
Life gets noisier every day and very few people can free from noise of some sort or another.It doesn′t matter where you live--in the middle of a modem city,or a faraway village--the chances that you will be disturbed by jet aero planes,transistor radios,oil powered engines,etc.,are almost everywhere.We seem to be getting used to noise,too.Some people feel quite lonely without background music while they are working.
Scientific tests have shown that total silence can be very frightening experience for human beings.However,some people enjoy listening to pop music which is very loud,and this can do harm to their eardrums（耳鼓）.The noise level in some disco is far above the usual safety level for heavy industrial areas.
One recent report about noise and concentration（专心）suggested that although a lot of people say that any noise disturbs their concentration,what really affects their ability to concentrate is a change in the level of noise.It goes on to say that a background noise,which doesn′t change too much（music,for example）may even help people to concentrate.
Scientists have discovered that what prevents people from concentrating is
A.anykindofnoise
B.greatchangesinlevelofnoise
C.background,noise
D.variousbackgroundmusic
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