旅游业属于第二产业。
参考答案:错
— Where is Lucy, Jane?
— I am not sure. _____. [ ]
A. She must have gone home
B. She can't have gone home
C. She should have gone home
D. She might have gone home
收受定金的一方不履行约定的债务的,应当()返还定金。
A.单倍
B.双倍
C.三倍
D.四倍