△ABC中,∠C=90°,AD平分∠BAC交BC于D,且BD:CD=3:2,BC

题型:填空题

问题:

△ABC中,∠C=90°,AD平分∠BAC交BC于D,且BD:CD=3:2,BC=15cm,则点D到AB的距离是(    )。

考点:角平分线的性质
题型:填空题

阅读理解

阅读下面短文,从每题所给的A、B、C、D 四个选项中选出最佳选项。

     How could we tell time if there were no watches or clocks anywhere in the world?

     The sun was probably the world's first "clock",except(除了) in the far north,where the

Eskimos(爱斯基摩人) live.There,it's dark most of the winter,and light most of the summer.

But in most of the world,people have used ck.Even today,if you don't have a clock,you still

know that when the sun shines,it's day ,and when it's dark,it's night.the sun can also tell you

if it's morning,noon,or afternoon.

     People who live near the sea can tell time from the tides.In the day time,for about six hours,

the water rises higher and higher on the beach.And then it goes down and down for about six

hours.the same thing happens again at night.there are two high tides and two low tides every 24hours.

     Seaman on a ship learn how to tell time by looking at the moon and the stars.The whole sky is

their clock.

     In some places in the world the wind comes up at about the same time every day or changes

direction or stops blowing.In these places the wind can be the clock.

     A sand clcok is an even better clock.If you had fine dry sand in a glass shaped like the

one in the picture,you would have what is called an hour glass.The sand in the hourglass goes

from the top part to the bottom part in exactly an hour.When the hourglass is turned over,the

sand will take another hour to go back again.

1.According to the passage,there are _______ ways to tell time besides the clock and the watch.

A. 3      

B. 4    

C. 5    

D. 7

2.The Eskimos can't use the sun for a clock because ________.

A.they know very little about the sun      

B.the sun there never goes down in winter.

C.It's too cold for them to go out to watch the sun  

D.It has long dark winters and long light summers

3. "tides" in the passages means ________.

A. 洋流    

B. 潮汐  

C.  海啸

D. 波浪

4. In which page of a newspaper can you most probably read this passage?

A. news    

B. science    

C. business    

D. advertisement(广告)

5. What's the best title?

A.Different Ways to Tell Time

B.Useful Machine to Tell Time

C.The History of the Clock    

D.The Development of the Clock

题型:填空题

分离脊髓灰质炎病毒(发病早期)最好采用()

A.咽漱液

B.粪便

C.血液

D.脑组织

E.尿

题型:填空题

辛味的药物能够()
咸味的药物能够()

B.缓急

C.收敛

D.泄降

E.软坚

题型:填空题

有关单克隆丙种球蛋白病发病特点,错误的是()。

A.疾病的突出特点是血清中存在异常增多的M蛋白

B.B细胞异常增殖

C.M蛋白主要来源于脾细胞的恶性增生

D.血清蛋白区带电泳可见特异性的M区带

E.尿液蛋白区带电泳可见特异性的M区带

题型:填空题

天平是根据()原理设计制造的,分析天平是指能称量到()克的精密天平。

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