会计要素按性质分为（）
A、资产
B、负债
C、所有者权益
D、资产负债共同类
参考答案：A, B, C
My sister met him at the Grand Theatre yesterdays afternoon, so he ________ your lecture.[ ]
A．couldn't have attended
B．needn't have attended
C．mustn't have attended
D．shouldn't have attended
电动机定子电流等于空载电流与负载电流（）。
A.之和；
B.之差；
C.相量和；
D.之比；
