多形性腺瘤的恶变率是
A．10%以下B．15%～20%C．30%左右D．50%左右E．60%以上
参考答案：A
解析：记忆题。
.Though the NMET is drawing near day by day, I still find I have so much to learn , to revise, to memorize and to analyze but without enough time. Oh, dear, everything seems to be____.
A．in a row
B．in a mess
C．in a mass
D．in a queue
C220最多支持（）个PON板。
A、4
B、8
C、10
D、12
