题目内容：
If a person wants to be left alone an elevator，the best thing to do is__________ ．
A．to look into another passenger's eyes B．to avoid eye contact with other passengers
C．to signal that he is not a threat to them
D．to keep a certain distance from other passengers
参考答案：【答案仅供学习，请勿对照自行用药等】
答案解析：