在△ABC中,已知∠C=90°,BC=3,tgB=2,那么AC=______.

题型:填空题

问题:

在△ABC中,已知∠C=90°,BC=3,tgB=2,那么AC=______.

考点:锐角三角函数的定义
题型:填空题

阅读理解。

     Nowadays some people like to buy what they want through the Internet, which really brings us lots of

conveniences. If you have a computer linked with the internet by telephone or another, you can just move

the mouse, fill in some forms about your personal information and the information of the company which

you are buying things from, then the clerk from the company will send what you need to you in a short time.

     However, some housewives don't always enjoy that way. They still like to walk around a shop or a

supermarket on one hand, they suspect the reality of the goods on the screen, because they buy the things

online only by eye not by ear or hand even or now; on the other hand, they think it is really a kind of relaxation

to walk around the shop or the supermarket, and sometimes it is an interesting thing to bargain with the

sellers. If they cut down lots of price, they will have a feeling of success.

1. People like to buy things through the Internet because _____. [ ]

A. The goods are at a low price

B. the goods are at a high price

C. it can bring people lots of conveniences

D. the goods are nice

2. People can get what they want through the Internet _____. [ ]

A. very slowly

B. very quickly

C. very expensive

D. very hard

3. The word "convenience" means _____ in Chinese. [ ]

A. 金钱

B. 商品

C. 货物

D. 方便

4. Some housewives enjoy shopping in a shop or a supermarket because _____. [ ]

A. it's a kind of relaxation to walk around a shop or a supermarket

B. it's very interesting to bargain

C. people can get a feeling of success by cutting the price down

D. A, B And C

5. The best title of the passage is _____. [ ]

A. Shopping online

B. How people can go shopping online

C. The convenience of shopping online

D. Women like shopping online

题型:填空题

下图所示各物质是由1~20号元素中部分元素组成的单质或其化合物,图中部分反应条件未列出。已知C、H是无色有刺激性气味的气体,D是一种黄绿色的气体单质,物质J可用于泳池消毒。反应②和④是化工生产中重要反应,反应⑤是实验室制备气体C的重要方法。

请回答下列问题:

(1)物质E的电子式是__________;I中所含化学键类型为:____________________;气体D所含元素在周期表中的位置是____________________。

(2)G的水溶液呈__________性,用离子方程式表示其原因___________________________。

(3)写出E与过量I溶液反应原离子方程式______________________________。

(4)写出实验室制备气体C反应的化学方程式______________________________,干燥气体C可选用__________做干燥剂(填名称)。

(5)写出反应④的化学方程式_________________________________。

(6)反应③的现象为______________________________。

(7)已知含7.4g I的稀溶液与200mL 1 mol/L的H溶液反应放出11.56kJ的热量,写出该反应的热化学方程式________________________________________。

(8)物质A由三种元素组成,1 molA与水反应可生成1 mol B和2 mol C,A化学式为______________________________。

题型:填空题

2011年通用承保政策中规定:个单业务中商业险出险()次及以上的不予承保。

题型:填空题

下图为某日北半球部分气压带、风带分布示意图,其中①、②、③分别代表气压带或风带,阴影代表气压带。读图完成问题。

该日,北半球正处于()

A.春季

B.夏季

C.秋季

D.冬季

题型:填空题

渣罐座是铸铁制造的,专门用作放置渣罐

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