The professor ( ) this morning is from the United States.A

问题描述:

The professor ( ) this morning is from the United States.A
The professor ( ) this morning is from the United States.
A arrived B arriveing C who arrived D to arrive
我感觉B和C貌似都对的

C 是对的,这里你要清楚,”到达“是已经完成的动作,应该是过去时态.