同义句转换，每空一词。

1. Could you please take the trash out? 

    _____ the trash _____, please.

2. Remember to make your bed. 

    ______ _____ to make your bed.

3. Please give food to my dog twice a day. 

    Please _____ my dog twice a day.

4. Who looks after your sick grandmother? 

    Who _____ _____ _____ your sick grandmother?

5. These are my cousins.

    These are cousins _____ _____.

根据张凌云的归纳，旅游学的研究对象可以归纳为（）。

A.关系---现象说

B.企业说

C.矛盾说

D.三要素说

E.经济说