―Where’s your father?

―He _____ abroad on business.

―Really? But he can’t _____ many English words.

A．has been, tell

B．has gone, speak

C．has gone, say

D．has been to, talk

某患者，右下6缺失，行双端固定桥修复。固定桥试戴时，用力戴入后，基牙出现胀痛不适，最可能的原因是

A．就位道不一致

B．邻接触点过紧

C．有早接触

D．出现电位差刺激

E．邻牙有根尖病变