.已知圆O1与圆O2内切,O1O2=5cm,圆O1的半径为7cm,则圆O2的半径为____.

题目
填空题
.已知圆O1与圆O2内切,O1O2=5cm,圆O1的半径为7cm,则圆O2的半径为____.
参考答案和解析
正确答案: 2cm或12cm
解析: 暂无解析
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相似问题和答案

第1题:

单选题
A

very

B

many

C

much

D

too


正确答案: D
解析:
more difficult是比较级,选项中只有much可以修饰比较级。

第2题:

单选题
A

table

B

wall

C

paper

D

bin


正确答案: A
解析:
句意:要两杯咖啡。其中一杯记在墙上。后文提到又有两个人进来,说“one on the wall”。由此可知,此处为“wall”,意为“墙”。table桌子。paper纸。bin垃圾桶。均未提及。

第3题:

单选题
Tom, more than anyone else, _____ anxious to go there again.
A

are

B

were

C

is

D

being


正确答案: B
解析:
句意:汤姆比其他任何人更渴望去那里。考查主谓一致。当用more than,along with,together等引导插入语时,谓语动词与插入语前的主语保持一致。所以此句真正的主语是Tom,be动词要与之保持一致,故选择is。此题答案选C。

第4题:

单选题
Of 654 respondents with children, 64% said ______.
A

they were often too busy to play with their children

B

they were often so tired that they couldn’t play with their children

C

they were often so sad that they didn’t want to play with their children

D

they were often ill and they couldn’t play with their children


正确答案: D
解析:
细节理解题。由第五段的第二句“Worryingly, of 654 respondents (离婚被告) with children, 64% said they were often too tired to play with them”可知,有64%的人觉得自己太累不能陪孩子玩耍。因此B项正确。

第5题:

单选题
—Lisa, hurry up! The bus is coming.—Oh, no. We ______ cross the street until the traffic lights turn green.
A

mustn’t

B

needn’t

C

should


正确答案: C
解析:
句意:——丽萨,快一点!公汽马上就来了。——噢,不行。在交通灯变绿之前我们不准过马路。本题考查情态动词的用法。根据语境这里要表达“禁止,不允许”的意思,只有mustn’t符合题意,因此选A项。

第6题:

单选题
如图所示的实验现象能够说明______的成像特点.(填选项前的字母)
A

照相机

B

幻灯机

C

放大镜


正确答案: B
解析:
图中,物距大于2倍焦距,成倒立、缩小的实像,A项照相机就是应用这一规律;

第7题:

单选题
They have done things they ought _____.
A

not to do

B

not to be done

C

not to have done

D

not having done


正确答案: D
解析:
句意:他们做了不该做的事。表示不该做而做了,可以用shouldn’t have done或ought not to have done,故为C。

第8题:

单选题
0.5mol某烃完全燃烧后,生成44.8L(标准状况下)CO2和36g水,该烃的分子式是(  ).
A

C4H10

B

C2H4

C

C4H8

D

C6H6


正确答案: D
解析:
由题意可知,1mol该有机物完全燃烧生成4mol二氧化碳和4mol水,因此,该烃的分子式为C4H8

第9题:

单选题
What does the underlined word “drags” probably mean?
A

Passes slowly.

B

Runs quickly.

C

Moves actively.


正确答案: A
解析:
【语篇解读】这是一篇说明文。题材是科普知识。科学家们通过研究发现了人们在快乐的时候时间过得快,而无聊时时间过得慢的原因。
词义猜测题。划线部分所在句表示“当我们快乐时会发现时间过得很快,而当我们无聊时,时间会…。”根据句意可知,前后表示对比,所以drags应该是“过得慢”的意思。故选A项。

第10题:

单选题
The manager decided to continue the sales for _____ two weeks because of the large stock of goods.
A

other

B

another

C

the other

D

others


正确答案: A
解析:
本题考查other和another的用法。句意:因为有大量库存,所以经理决定将销售时间再延长两个星期。本题中的another two weeks意为“多两周”,与two more weeks同义。在四个选项中,只有another意思与more相似,故B项为正确答案。the other表示在限定范围内的另外一个。