测定水中溶解或乳化油的含量时,要在水面下()cm处采集水样。
A、5~10
B、10~15
C、15~20
D、20~25
参考答案:A
– You won the first prize in the physics contest !
-- ________ ! I made several terrible mistakes .
A.I think so
B.You must be joking
C.You must be serious
D.I’m afraid so
肺炎最佳分类方法是按()
A.解剖部位
B.病情
C.病因
D.病理
E.病程