复方丹参注射液中有丹参和降香,所以提取方法应为
A.蒸馏法
B.水提醇沉淀法
C.蒸馏法和水提纯沉淀法结合的综合法
D.萃取法
E.酸碱沉淀法
参考答案:C
If it had not been for your help, I ____ the examination.
A.could not pass
B.would not pass
C.would not have passed
D.can not have passed
应设有准备状态,雷达从准备开始在()内应进入工作状态。
A、10s
B、15s
C、30s
D、45s