下列试样既能用密度瓶法又能用韦氏天平法测定其密度的是（）
A、丙酮
B、汽油
C、乙醚
D、甘油
参考答案：D
进入煤气区域，佩带便携式报警器一人也可进入。
Yang Ziqiong is said to __________ in the film Rain of Swords.
A．act leading part
B．make a leading role
C．play leading part
D．play a leading part
