高频高压引弧需要在电极和工件之间加上()V的空载电压。A.220-380 B.38

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问题:

高频高压引弧需要在电极和工件之间加上()V的空载电压。

A.220-380

B.380-500

C.500-2000

D.2000-3000

考点:燃油燃气锅炉司炉工燃油燃气锅炉司炉工题库
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朱丹溪的医学著作主:要有哪些 试述丹溪学说形成之渊源

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Do you know how to prepare for and survive a major earthquake? According to Department of Conservation scientists, it is important to have the right answer to that question.

How to Be Prepared

Electricity, water, gas and telephones may not be working after an earthquake. The police and fire departments are likely to be tied up. You should be prepared to fend for yourself at least three days,preferably for a week. You’ll need food, water and so on. It’s also a good idea to decide ahead of time how and where your family will reunite if separated during a quake. You might choose an out-of-the-area friend or relative that family members can call to check on you.

________

If you’re indoors, stay there. Get under a desk or table. The kitchen is a particularly dangerous spot. If you’re in an office building, stay away from windows and outside walls and do not use the elevator. If you’re outside, get into the open. Stay clear of buildings, power lines or anything else that could fall on you. If you’re driving, move the car out of traffic and stop. Avoid parking under or on bridges or overpasses.

After an Earthquake

Check for fire. If you smell gas, shut off the main gas valve(阀). If there’s sign of damage to electricial wiring, shut off the power at the control box. If the phone is working, only use it in case of emergency(紧急情况). Avoid driving if possible to keep the streets clear for emergency vehicles. Be careful that things may fall out of cupboards when the door is opened, and also that chimneys can be weakened and fall with just a touch. Listen to the radio for important information and instructions. Remember that aftershocks, sometimes large enough to cause damage in their own right, generally follow large quakes. If you leave home, leave a message telling your friends and family your location.

小题1:

The underlined phrase“tend for’’ in the second paragraph probably means“ ________’’

A.look for

B.take care of

C.be proud of

D.think of小题2:

Which of the following would be the best subtitle for the third paragraph?

A.Before an Earthquake

B.After Making Preparations

C.While Staying at Home

D.During an Earthquake小题3:

What should you do when an earthquake happens?

A.You should stay away from the kitchen.

B.You should drive on a bridge.

C.You should turn off the power.

D.You should listen to the radio frequently.小题4:

What will probably happen after a big earthquake?

A.The local people’s life will return to normal in a week.

B.There will be more earthquakes in a short time.

C.There won’t be any earthquakes in a short time.

D.The local people will stay at home waiting for help.

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不分散低固相聚合物钻井液配制时,要用纯碱除掉配浆水中的Ca2+。

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增值税小规模纳税人从事货物、服务、无形资产销售,提供加工、修理修配劳务的,应合计计算销售额。月销售额不超过3万元(按季纳税9万元)的,自2016年5月1日起至2017年12月31日,可享受小微企业暂免征收增值税优惠政策。

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德山位于常德市武陵区东南,主峰孤峰岭海拔97.6米,形如青螺,风景秀丽。

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