下列实验操作中正确的是[ ]
A.熄灭酒精灯
B.滴加液体
C.过滤
D.稀释浓硫酸
答案:B
She’s already two hours late. What ______ to her?
A.can have happened
B.may have happened
C.should have happened
D.must happen
建筑市场诚信行为记录信息的公布时间,应不超过行政处罚决定做出后的()。
A.7天
B.15天
C.20天
D.30天