1 She brought forward a plan we couldn't accept.A/ B for which C to which D of which (A)--which.做accept 的宾语,不用加介词,如果是the school which I study in ,把in提前就是the school in which I study.School 不是 study的宾语
2 The English subject ,I have mastered well ,is important in middle school.A / B at whivh C that Din which ( A)--同上.
3 The place you visited during your holidays is where I used to be for years.A Where B which C that D to which (A)--visit可接宾语也可不接,用which 和where 均可,但要与后面 where 保持一致最好.
4 Tom ,we had expected,got the 1st place in the competition.A as B which C whom D who (A)--状语从句,并非定语从句.
5 The wolves hid themselves in the places couldn't be found.A that B where C in which D in that (A) --只有That是能做宾语,其它的都是状语,而found是接places做宾语的.
6 The freezing point is the temperature water changes into ice.A at which B on that C in which D of what (A)
---point是个温度点,要用at ,这是考at和IN,前者指精确的地点和时间,后者指一个范围.