John doesn’t work hard at his lesson and feels really nervous with the final exam _________.

A．approached

B．to be approached

C．being approached

D．approaching

下面有关肛瘘的说法是正确的有（）。

A.一般由原发性内口、瘘管和继发性外口三部分组成

B.局部反复流脓、疼痛、瘙痒

C.肛瘘常为肛周脓肿继发病变，是肛周脓肿的自然结局之一

D.一般分为单纯性和复杂性两类

E.以上均是