詞匯用法

定語從句：代詞/名詞/數(shù)詞﹢of which/whom

①I was given three books on cooking, _________　_________　_________　_________ I really enjoyed．(它們中的第一本)

② have many friends, _________　_________　_________ are businessmen．(他們中的一些)

③It is reported that two schools, _________　_________　_________ are being built in my hometown, will open next year．(它們兩個(gè))