---Do you know _______?

---At the end of July.

A．how soon is your sister coming back home

B．how often Nancy hears from her pen friend[

C．when the London Olympic Games were held

D．when will the new computer game come out

下列属于政府采购的对象范围的有（）。

A.采购办公用品

B.采购工程

C.对办公楼进行改扩建

D.租赁固定资产