we need some food _____because we’ll have a barbecue tomarro

we need some food _____because we'll have a barbecue tomarrow.A to buy B buying C buys D bought
1 we need some food _____because we'll have a barbecue tomarrow.
A to buy B buying C buys D bought
2 this hat is too big.please show me a ____ one.
Asmall B big C smaller D bigger
3 my father often ___newspapers after supper.
A reads B sees C looks D watches
4 the Pacific is _______ ocean.
A a B any C an D the
请说明理由,方法.

1A need sth to be done
2C 因为帽子太大,要一个小一点的
3A read newspapers
4C 元音发音前用an