中国左翼作家联盟成立于（）年。
A.1928
B.1930
C.1937
D.1942
参考答案：B
A brilliant idea suddenly ______ me when I was in trouble.
A．happened
B．occurred
C．struck
D．came
与电流相量I=4+j3对应的正弦电压可写作i=（）。
A.A
B.B
C.C
D.D
