一套建筑面积100m²、单价3000元/m²、总价30万元的住房，在实际交易中，双方约定，从成交日期时起分期付清，首期支付10万元，余款在一年内分两期支付，每隔半年支付10万元。假设年折现率为5%。则该住房的实际单价为( )元/m²。

A．2928

B．3000

C．2857

D．2850

用所给单词的正确形式填空 (10%)

小题1:How long have you been _______ (collect) shells?

小题2:I was _______ (annoy) by his bad manners.

小题3:Why don’t you ______ (buy) a calendar for her?

小题4:Have you ever ______ (be) to Disneyland?

小题5:There is nobody in the classroom, ______ (be) there?