罗马帝国的建立者是[ ]
A．伯利克里
B．屋大维
C．恺撒
D．汉尼拔
答案：B
What colour is your vest? [ ]
A. It's white.
B. It's 25 yuan.
C. It's a vest.
扬声器发出开车预警（）次后，胶带输送机正常启动。
A.1
B.2
C.3
D.4
