In 1982 the median income for married-couple families with a wage-earning wife was $9,000 more than (that for families in which only the husband) was employed.
——OG 137作者: tongxun 时间: 2002-10-26 17:58
这个是用的in which 。一般which引导这种定语从句，其前面都有介词。
in which =that作者: princess 时间: 2002-10-26 19:03
