You ’d better be careful, Linda. The knife is sharp.— _____, Mum.

Is John coming by train —He should,but he ________ not. He likes driving his car.

下列句子中，加横线词语的用法不同于其他三项的是（ ）

It might have been John _____ bought a present for Mary yesterday.

All men are created equal and every child has the equal right to receive education _______ their financial background.