He bought a new pair of trousers.

他买了一条新裤子。

I need to buy a new pair of trousers.

我需要买一条新的长裤。

He bought a new pair of trousers for the meeting.

他为会议买了一条新裤子。

I need a new pair of trousers to go with this jacket.

我需要一条新裤子来配这件夹克。

Xiao Ming wears a new pair of trousers.

小明穿了条新裤子。

I really need a new pair of trousers.

我真的需要一条新裤子。