I'm afraid there ______ much time left. Let's hurry.[ ]
A. isn't
B. aren't
C. is
答案:A
权益集合法
关于慢性根尖周炎的分型,下列哪一项是错误的()
A.根尖肉芽肿
B.黏膜下脓肿
C.慢性根尖脓肿
D.根尖囊肿
E.致密性骨炎