疼痛是牙髓炎的突出症状，医师应注意询问()

A．刺激因素

B．性质

C．部位

D．时间

E．以上各项

(2013·厦门第一次适应性考试)When my father is upset, he would rather ________.

A．leave alone

B．we left him alone

C．left alone

D．we leave him alone