定语从句是整个高一英语语法的重中之重，请同学们结合所学将下列十句话进行改错，每处错误仅涉及一个单词的增加、删除或修改。
增加：在缺词处加一个漏词符号（∧），并在其下面写上该加的词。
删除：把多余的词用斜线（＼）划掉。
修改：在错的词下划一横线，并在该词下面写上修改后的词。
【小题1】The baby which Tom is looking after is his brother.
【小题2】My friend is the boy who T- shirt is black.
【小题3】There was a time what the businessman lost heart.
【小题4】The reason why she gave was not true.
【小题5】Frederick William I , whom the amber room belonged, decided not to keep it.
【小题6】Cindy is a lovely girl, with that many people like to make friends.
【小题7】This is the room, the roof of whom is red.
【小题8】Which we all know, China is a developing country.
【小题9】This is the book which I bought it yesterday.
【小题10】He is a student who have a gift for maths.