When _________ different cultures, we often focus our attention on the differences without noticing many similarities.

A．having compared

B．compared

C．being compared

D．comparing

声门上型喉癌的早期症状是（）。

A.咽喉疼痛，吞咽时疼痛加重

B.咳嗽，痰中带血

C.声音嘶哑

D.仅有喉部不适感或异物感

E.呼吸困难