【判断题】【消耗次数：1】
步进电动机是否转动是由控制绕组中输入脉冲的有无来控制。
①
正确
②
错误
参考答案：
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相关题目
【单选题】
在机床电力拖动中要求油泵电动机启动后主电动机才能运行，接触器KM1控制油泵电动机，接触器KM2控制主电动机，则在控制电路中必须( )。
①
KM1的动合触点串入KM2的线圈电路中
②
KM1的动断触点串入KM2的线圈电路中
③
KM2的动断触点串入KM1的线圈电路中
④
KM2的动合触点串入KM1的线圈电路中
随机题目
【单选题】
He _____ the old ladywith 10 pounds for bringing back the lost dog
①
rewarded
②
prized
③
gave
④
paid
【单选题】
9.We should really take some effective ______ to prevent such terrible things from happening again.
①
measures
②
steps
③
means
④
ways
【单选题】
11.Andrew was determined to ______ a computer career after graduation.
①
apply
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shave
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purse
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select
【单选题】
At the bus stop _____ a soldier and two young people on their way to North Carolina.
①
were
②
was
③
is
④
waiting
【单选题】
12.Among these articles, which do you think are most ______ to interest our students?
①
competent
②
likely
③
awkward
④
unexpected
【单选题】
2.I couldn’t understand why he pretended ______ in the bookstore.
①
to see me not
②
not to see me
③
not see me
④
to see not me
【单选题】
In the meantime, the question facing business is whether such research is _____ the costs.
①
worth
②
worth of
③
worthy
④
worthwhile
【单选题】
7. They hope to_________the source of the infection.
①
track down
②
look down
③
look at
④
back down
【单选题】
1.The movie star ______ with your sister, didn’t he?
①
was used to dance
②
used to dancing
③
used to dance
④
was used to dancing
【单选题】
7.We had warned him________the danger but he turned a deaf ear to our warning.
①
to
②
along
③
in
④
of