1、The knife we cut the bread is very sharp.A．which B．with C．

D 用来切面包的那把刀很锋利.The knife（with which) we cut the bread is very sharp
再问： 为什么不能用which
再答： 如果说只用which句子不完整。把它分成两个句子你就明白了 The knife is very sharp . We cut the bread with the knife.