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【多选题】
L7变频器出现“UV1”主回路低电压故障代码时,可能的原因是( )。A.
电源电压波动大
B.
电机负载过大
C.
电源输入缺相
D.
加速时间太短
E.
电源输入端子接线松
F.
发生瞬时停电
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举一反三
【单选题】Which of the following italicized parts is used as an object?
A.
What do you think has happened to her?
B.
Who do you think the visiting professor is?
C.
How much do you think he earns every month?
D.
How quickly would you say he would come?
【单选题】What ________ if there ______ no water or air on the earth?
A.
happen, is
B.
will happen, is
C.
will happen, will be
D.
happen ,are
【单选题】I didn't know what to do but then an idea suddenly ______ to me.
A.
occurred
B.
entered
C.
happened
D.
rushed
【单选题】—What _____ to your village in recent years? —Lots of roads, buildings, parks and so on.
A.
have happened
B.
happened
C.
has happened
【单选题】－I can't walk any longer, Mum. －Why? _____, dear? [ ]
A.
What has happened to you
B.
What did you happen
C.
What have you happened
D.
What is happened to you
【单选题】The police said they would not give up looking into other possibilities ____they find out what happened.
A.
as
B.
while
C.
until
D.
although
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