Question

It’s necessary ______ us to keep our pets clean everyday.

A．of

B．for

C．with

D．between

Answer 1

B

“It is + adj.+ of sb.+ to do sth”句型中的adj.跟sb.有關(guān),這個(gè)adj.是用來(lái)形容sb.的,表示某人這么做真是太adj.了。如：It’s very kind of you to help me.而“It is + adj.+ for sb.+ to do sth”表示做某事對(duì)某人來(lái)說(shuō)很adj.，這里的adj.是do sth的屬性，里面的sb.跟adj.沒(méi)有直接聯(lián)系。故根據(jù)句意選B。