验证酶的高效性实验成功的关键是[ ]
A.试管是否干净
B.肝脏是否新鲜
C.卫生香(或火柴梗)是否点燃
D.是否有对比实验
答案:B
He gave up _______ two years ago. That’s to say, he is a non-smoker now.
A. smoke B. smoking C. to smoke
银行业从业人员对所在机构的纪律处分有异议时,可以直接向监管部门反映和申诉。()