头面痛的特点是单面颜面______发作的疼痛，其疼痛呈______痛、______痛，多在______发作。
参考答案：反复 刺 胀 白天
—Don’t you feel surprised to see Bruce at the meeting ?
—No. I really didn’t think _____________ here .
A．he has been
B．he had been
C．he would be
D．he would have
DWDM中的关键技术有（）。
A.光源技术
B.光调制技术
C.合波分波技术
D.光放大技术
