目前临床使用最多、效果最好的一类透析器是什么？
参考答案：
空心纤维透析器
He is no longer in good condition, and his ability to work is limited. I _______ him to give up the job but failed.
A．suggested
B．persuaded
C．tried to persuade
D．managed
货运合同应纳印花税为( )元。
A．40
B．35
C．21
D．70
