-- Your uncle speaks good English. Who taught him?

-- ________, he learned it by himself.

A．To begin with

B．To my surprise

C．To be honest

D．Thanks to

关于咽旁间隙，描述正确的是（）

A.位于咽的后方

B.下颌智齿冠周炎可引起该间隙感染

C.不会出现吞咽困难

D.颈部舌骨大角平面无压痛

E.可扩散至前纵隔