在一个正方形花坛的四周栽树,要求4个顶点各栽1棵,每边只栽10棵,共栽了( )棵

题型:选择题

问题:

在一个正方形花坛的四周栽树,要求4个顶点各栽1棵,每边只栽10棵,共栽了(  )棵树.
A.36B.32C.48D.40
考点:植树问题
题型:选择题

We live in the computer age. People use computers to do much of their work. But few people know how to look after them. Remember the following when you use your computer:

1.Keep your computer in a cool, dry room. Too much or too little heat is bad for computers. Damp(潮湿) is also bad for them.

2.Do not let people smoke near your computer. Smoke of all kinds is very bad for many parts of a computer.

3.Do not eat or drink when you are near your computer. Pieces of food and a little water in the keyboard are also bad for a computer.

4.Keep your screen clean and do not have it too bright. They are bad for your eyes. Make sure the screen is not too far from or too near your eyes. Some people use different glasses to protect their eyes when they use a computer.

小题1:Computers can          people to do a lot of work.

A.use

B.help

C.make

D.take小题2:Few people know how to          their computers.

A.look at

B.try out

C.look for

D.take care of小题3:A computer works well at a temperature of         .

A.0℃

B.-5℃

C.20℃

D.35℃小题4:Smoke is not good for many parts of a computer, is it?

A.Yes,it is.

B.No,it isn't.

C.Yes,a little.

D.Not at all.小题5:A dirty screen or a very bright screen is    for your eyes.

A.bad

B.good

C.useful

D.helpful

题型:选择题
如果分式
2
x-1
3
x+3
的值相等,则x=______.
题型:选择题

2012年11月18日,贵州省六盘水某煤矿发生瓦斯爆炸事故,其中17人下落不明.瓦斯(化学式为X)燃烧时发生如下反应:

X+2O2═CO2+2H20,X的化学式为    ,为了防止瓦斯爆炸,煤矿的矿井里必须采取         等安全措施.

题型:选择题

下列物质中,化学键类型相同的一组是

A.NaCl、HCl

B.MgCl2、SO2

C.KCl 、CCl4

D.CO2、H2O

题型:选择题

以下哪穴不属于特定穴:

A.石门
B.腕骨
C.头维
D.后溪
E.关元俞

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