They had a party _______ the evening of October 1. [ ]

A. in

B. at

C. on

D. /

两个共点力F₁与F₂的合力大小为6N，则F₁与F₂的大小可能是（　　）

A．F₁=4N，F₂=8N

B．F₁=2N，F₂=9N

C．F₁=1N，F₂=8N

D．F₁=2N，F₂=1N