此题中 be necessary for 和 to的区别,为什么不能用to啊
just as there are occupations that require college or even higher degrees, so too are there occupations___technical training is necessary.
A. for which B. to which
解析说的是 定语从句,be necessary for 表示 对...来说是必要的. be necessary to 不也表示 对...来说是必要的吗,to 后面也可以加sth. 啊.