对细菌耐药率超过（）的抗菌药物，应该慎重经验用药。
A.30%
B.40%
C.50%
D.60%
参考答案：B
Jeremy Shu-How Lin, NBA star, is one of _____ few basketball players who are very popular
to Chinese fans. [ ]
A. an; the
B. the; a
C. a; the
D. an; a
计算机操作系统中，若P、V操作的信号量S初值为2，当前值为-1，则表示有( )个等待进程。
A．0个
B．1个
C．2个
D．3个
