請(qǐng)看例句：

　　It is a bad time for buying a house.

　　It is a bad time to buy a house. (用動(dòng)詞不定式也可以)

　　現(xiàn)在是不適宜于購置房產(chǎn)的時(shí)期。

　　This beach is good for swimming but bad for surfing.

　　這片海灘適宜游泳而不適合作沖浪運(yùn)動(dòng)。