Tom ______ in China now. He called his parents once a week.[ ]

A. is studying    

B. will study      

C. has studied    

D. studied

住宅使用说明书一般应包含的内容有( )。

A．结构类型

B．开发单位、设计单位、施工单位、物业管理单位

C．配电负荷

D．门、窗类型，使用注意事项

E．装修、装饰注意事项