粗盐初步提纯的操作步骤如图所示,相关说法错误的是( )
A.溶解时玻璃棒用于搅拌
B.过滤时玻璃棒用于引流
C.蒸发至滤液被蒸干后再移去酒精灯
D.图中“操作1”是称量
答案:C
改善乘客购票兑零时排长队的基本原则是什么?
Some of you have finished Book One.________, you can go on with Book Two.
A.If you may
B.If you do
C.If not
D.If so