宴会中的凉菜应在开席前（）上桌。
A.5min
B.10min
C.15min
D.30min
参考答案：C
In relation to companies limited by shares:
(a) Explain the rights of ordinary shareholders. (3 marks)
判断导体的感生电动势方向时，（）所指的方向为在导体中产生感应电动势方向。
A.左手大拇指
B.右手大拇指
C.左手四指
D.右手四指
