既能用where又能用in which的情況：

　　引導定語(yǔ)從句，在定語(yǔ)從句中作地點(diǎn)狀語(yǔ)，從句與先行詞的搭配缺少介詞in時(shí)，既能用where又能用in which。

　�。�1）This is the house where/in which he used to live.

　　這是他過(guò)去住的房子。

　�。�2）The old school has now turned into a large modern factory where/in which a lot of coulour TV sets are produced every year.

　　這所舊學(xué)�，F在已變成一個(gè)大型的現代化工廠(chǎng)，每年生產(chǎn)許多彩色電視機。