压差阻力与()因素有关。A.飞行器形状 B.飞行器表面状况 C.升力 D.机身尾部形

题型:单项选择题

问题:

压差阻力与()因素有关。

A.飞行器形状

B.飞行器表面状况

C.升力

D.机身尾部形状

考点:科普知识竞赛航空科普知识航空科普知识题库
题型:单项选择题

下列食物中富含维生素的是(  )

A.牛奶

B.白糖

C.青菜

D.植物油

题型:单项选择题

Do you know about the flu? The flu germs usually spread quickly. In winter, lots of people may get the flu. If you do get sick, do you know what to do? Here are some tips.

Drink lots of water. Water is good for your body especially (尤其) when you get the flu.

Get plenty of sleep and take it easy. If you can’t sleep, you can listen to music, watch a movie or read a book to relax yourself.

If you feel serious, ask your parents to take you to see the doctor. But don’t take any medicine until you see the doctor.

Wash your hands often! You certainly don’t want to spread the flu to anyone else. Also, don’t share (共用) cups and eating utensils (餐具), like forks, with other people.

Most people who get the flu may get better without going to see the doctor. They will get better in about a week. But if you have a high temperature for more than a few days, call your doctor at once.

根据短文内容,回答下列问题。

小题1:Do the flu germs spread quickly?

_______________________

小题2:What can you do to relax yourself if you can’t sleep?

_______________________

小题3:If you feel serious, what mustn’t you do before seeing the doctor?

_______________________

小题4:Why can’t you share forks with others if you get the flu?

_______________________

小题5:How long does the flu usually last?

_______________________

题型:单项选择题

下列各种光现象的说法中表述正确的是(  )

A.盛了水的碗,看上去好像变浅了是由于光的反射形成的

B.太阳光穿过茂密的树叶,在地面上留下圆圆的光斑是由于光的直线传播形成的

C.人在照镜子时,总是靠近镜子去看,其原因是靠近镜子时,平面镜所成的像会变大

D.在暗室里,为了能从镜中看清自己的脸部,应使手电筒正对镜子照射

题型:单项选择题

高炉内煤气分布为两次分布,即炉缸和炉身分布。

题型:单项选择题

进行锁定作业时,上锁人与解锁人应为(),并正确记录上锁及解锁时间,不可在未解锁时就提前登记解锁时间。

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