S700K转辙机锁闭铁的正常弹出使速动开关的有关启动接点()或()表示()。
参考答案:闭合;断开;接点
Bob is determined to get a seat for the concert _______ it means standing in line all night for the ticket.
A.so that
B.as if
C.even though
D.however
用亲脂性有机溶剂提取总生物碱时,一般
A.先用酸水湿润药材
B.先用碱水湿润药材
C.先用石油醚脱脂
D.用正丁醇、乙醇等溶剂提取
E.用氯仿、苯等溶剂提取