导游服务是随着()旅游活动的出现而产生的。
A.社会性
B.商业性
C.参与性
D.享乐性
参考答案：B
It is said that there ______ a concert this Saturday. Do you want to go? [ ]
A. is going to have
B. will have
C. is going to be
D. will be having
单一资金池定价法
