1号线、2号线一侧屏蔽门滑动门共计多少对门,编号原则是什么?
参考答案:
一侧屏蔽门共计24对滑动门,编号原则为面向屏蔽门从最左边开始从1开始,从小到大,依次编号。
()Na+可用醋酸铀酰锌检出。
Oh! I ___ you ___ in Beijing.How long have you been here?
A.don’t know.. were
B.hadn’t known.. were
C.haven’t known.. are
D.didn’t know.. were