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【单选题】
信号 f 1 ( t ) 和 f 2 ( t ) 的波形如图所示 , 设 f ( t )= f 1 ( t )* f 2 ( t ) , 则 f (0) 等于 ( )A.
0
B.
1
C.
2
D.
3
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举一反三
【单选题】. —Peter looks sleepy. —So ________ if you had a fever.
A.
did you
B.
would you
C.
you did
D.
you would
【单选题】－He looks very hot and dry. －So______if you had a temperature of 40℃.
A.
would you
B.
will you
C.
would have you been
D.
do you