1 . The rich businessman purchased a vase for 300, 000 dollars last year. (改为否定句)
The rich businessman __________ _________ a vase for 300, 000 dollars last year.

2 . Mr. Smith, at the age of 30, ________ a house he really liked ________ just 150 thousand dollars.

A．spent; on

B．paid; for

C．purchased; for

D．cost; with

4 . 马西常常在跳蚤市场买一些有用的物品。
Marcy often ________ some ________ things in the flea market.

5 . Jack Ma often p______________ books and stationery for poor students.