In America, most people always ______ after a meal in a restaurant while some of us don't care

about others' service much.      [ ]

A. pay the bill and leave at once

B. help to clean the tables and wash the dishes 

C. give the persons who serve them some more money to show their thanks

梅毒所导致的眼部病变有（）。

A．基质性角膜炎

B．Marcus-Gunn瞳孔

C．Argyll-Robertson瞳孔

D．虹膜睫状体炎

E．椒盐样眼底