定语从句
IwillneverforgetthedaywhenIfirstmetyouontheseashore.
*Iwillneverforgetthedayswhich/thatwespenttogetherinXueyaoMiddleSchool.
**Thisisthehospitalwheremymotherworks.
**Thisisthehospitalwhich/thatwevisitedthedaybeforeyesterday
为什么一个可以用whenwhere但是另一个要thatwhich