试题与答案

已知|a|=3,|b|=8且a与b的夹角为120°,则a在b方向上的投影为( )

题型:选择题

题目:

已知|
a
|=3,|
b
|=8且
a
b
的夹角为120°,则
a
b
方向上的投影为(  )
A.4B.
3
2
C.-
3
2
D.-4

答案:

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下面是错误答案,用来干扰机器的。

答案:C本题考查判断汉字正误的能力。结合每个句子的具体语境来判断即可。

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题型:阅读理解

Everyday rubbish could provide a valuable source of energy thanks to a clever new invention. Smelly methane(沼气)gas expelled from landfill sites containing tones of rotting household waste could be used to produce a valuable energy resource. In Europe alone land fill tips produce 94 billion cubic meters of methane per year but currently only one percent of what could be a valuable source of energy is used, the rest is burnt off to prevent an explosive build up of gas.

Methane gas forms when organic matter breaks down and is drawn off from large rubbish tips by pipes sunk into the middle of the waste. Until now this process wasn’t possible on small sites because the pipe allowed oxygen to seep in and that stop the breakdown process.

Viktor Popov of the Wessex Institute of Technology has now developed a system to modify existing landfill sites by making them airtight while the methane is extracted from sunken wells. The site is covered by a special three-layered skin whose two outer layers are made of clay with a pressurized(加压的)layer of carbon dioxide gas in the middle. As the methane is sucked out through a central well it is replaced by carbon dioxide from the middle layer rather than oxygen, allowing the breakdown process to continue.

Unfortunately there are no plans to use the power of methane even though Popov claims his invention could provide a valuable source of energy over the next 20 years.

小题1:The passage mainly introduces ______ to us.

A.how to make methane

B.a new way to make use of rubbish

C.the valuable things in rubbish

D.the amount of rubbish beig reused小题2:From the passage we can see that _____.

A.in Europe 94 billion cubic meters of methane is produced every year

B.some of the waste will explode if it is not burnt off

C.99% of the rubbish has been burnt off in Europe

D.only a very small part of this kind of energy is used in Europe小题3:In the passage the underlined word “that” refers to ______.

A.methane gas

B.the long pipe

C.oxygen

D.the rubbish小题4:Which of the following statement is NOT true according to the passage?

A.Oxygen can cause the breakdown process to stop.

B.When the methane is sucked out, oxygen will enter from the middle layer.

C.Carbon dioxide doesn’t affect the breakdown process.

D.The new invention has not been put into use.

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题型:单项选择题

在窗体上画一个通用对话框,其名称为CommonDialog1,然后画一个命令按钮,并编写如下事件过程: Private Sub Command1_Click()CommonDialog1.Flags=cdlOFNHideReadOnlyCommonDialog1.Filter="All Files(*.*)|*.*|Text Files"_"(*.txt)|*.txt|Batch Files(*.bat)|*bat"CommonDialog1.Filter Index=2CommonDialogl.ShowOPenMsgBoxCommonDialog1.filename End Sub 程序运行后,单击命令按钮,将显示一个“打开”对话框,此时在“文件类型”框中显示的是 ______。

A.All Files(*.*)

B.Text Files(*.tx

C.Batch Files(*.ba

D.不确定

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