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【简答题】
已知工频f=50Hz,求周期T和角频率
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皮皮学刷刷变学霸
举一反三
【单选题】(2013·河北唐山模拟)The bell rang and every student had to ________ their examination papers.
A.
give up
B.
give away
C.
give out
D.
give in
【单选题】His opinion was quite ______ so we had to give up persuading him.
A.
clear
B.
apparent
C.
evident
D.
obvious