问题
单项选择题
()is the disadvantage for air transportation?
A. Quick but not safe
B. Less frequency
C. It can’t lift heavy goods
D. the highest cost in all transport modes
答案
参考答案:D
()is the disadvantage for air transportation?
A. Quick but not safe
B. Less frequency
C. It can’t lift heavy goods
D. the highest cost in all transport modes
参考答案:D