()将起爆药卷与炸药装在同一爆炸材料容器内运往井底工作面。
A.可以
B.不宜
C.严禁
参考答案:C
已知等差数列{an}中,a2=5,a4=a1-12.
(Ⅰ)求数列{an}的通项公式;
(Ⅱ)当Sn取最大值时求n的值.
---_________ does he take this medicine?
---Twice a day.
A.How long
B.How often
C.How soon
D.How much