通常状况下除去混合物中所含杂质的方法，正确的是[ ]物质所含杂质除去杂质的方法A

发布时间：2017-07-16 18:23 │ 来源：www.tikuol.com

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通常状况下除去混合物中所含杂质的方法，正确的是[ ]

	物质	所含杂质	除去杂质的方法
A.	CuSO₄粉末	Fe粉	加水充分搅拌；过滤；将滤液蒸发结晶
B.	C粉	CuO粉末	加入过量稀盐酸，充分反应后，过滤，干燥
C.	CO₂气体	CO	通入氧气，点燃
D.	MnO₂	KClO₃	充分加热后冷却

考点：物质的除杂

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的定义域为（　　）

B．（-2，+∞）

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阅读下面的短文，根据短文内容，完成表格。（每空填1至3个词）

China has decided to stop the use of free plastic bags. Supermarkets, shops and outlets (经销店) in
China can't offer plastic bags any more.
Every year, people use too many plastic bags. They throw them here and there after they have used
them. The government has done its best to deal with them but failed. While we offer quick service (服务)
to customers, the plastic bags pollute water, earth and air, and they waste the oil. The government asks
people to go back to carry cloth bags and use baskets when they go to buy something. The cloth bags
and the baskets can be used again and again. Many months have passed. The environment has been
improved a lot.

Action	Make a decision to stop the use of 1.
2.	Supermarkets, shops and outlets
Advantage	Offer 3. service to customers
Disadvantage	Pollute water, earth and air and waste 4.
What should we do	Go back to carry cloth bags and use 5.

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CORELDRAW中我们可否将选定对象精确定位（）

A.可以

B.不可以

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在光滑水平面上有一物块受水平恒力F的作用而运动，在其前方固定一个轻质弹簧，如图所示，当物块与弹簧接触并将弹簧压至最短的过程中，下列说法正确的是（　　）

A．物块接触弹簧后立即做减速运动

B．物块接触弹簧后先加速后减速

C．当物块的速度为零时，它受到的合力为零

D．当弹簧处于压缩量最大时，物块的加速度等于零

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输油臂遥控装置接收机由（）驱动相应的继电器去控制电控柜完成相应的指令动作。

A、地址码

B、数据码

C、逻辑码

D、机器码

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