you don't know the answer.l don't know------1.too2.either3.also4.neither

you don't know the answer.l don't know------1.too2.either3.also4.neither
you don't know the answer.l don't know------
1.too
2.either
3.also
4.neither

you don't know the answer.l don't know------1.too2.either3.also4.neither
选择2,用排除法,因为too和also都是用于肯定句,neither是两者都不,后面要跟nor

2.either

选B呀，把这句读100遍，就记得了……固定用法的说

选either，当表示“也……”的时候，too用于肯定句，只有either能用于否定句，also不能放于句末，而neither是对两者的全部否定。