3.[音频]听录音回答3-5题
A. To have better opportunities.
B. To improve his skills.
C. To work fewer hours.
D. To get a higher salary.
4
A. For six years.
B. For five years.
C. For three years
D. For two years.
5
A professor.
B. A manager.
C. An engineer.
D. A designer.
下列哪种物质不是化工原料的“三苯”?()
A. 苯
B. 甲苯
C. 乙苯
D. 二甲苯