Let me .[ ]
A. have a try
B. has a try
C. want a try
答案：A
下列四个命题中.正确的有
①若a>b，则a+1>b+ 1；
②若a>b，则a-1>b-1；
③若a>b，则-2a<-2b；
④若a>b，则 2a<2b. [ ]
A.1个
B.2个
C.3个
D.4个
一般药物一煎沸后应再煎( )
A．5～10min B．15min C．20min D．25min E．30min
