Some of the exercises appear to be ____ ones that you have done, but after taking ____ second look, you will

find that they are different. [ ]

A. /, the

B. the, the

C. the, a

D. /, a

房地产开发企业应当在商品房交付使用之日起( )日内，将需要由其提供的办理房屋权属登记的资料报送房屋所在地房地产行政主管部门。

A．30

B．60

C．90

D．120