细菌性角膜炎发病的危险因素有（）.
A.维生素缺乏
B.长期使用免疫抑制剂
C.干眼症
D.糖尿病
E.角膜接触镜
参考答案：A, B, C, D, E
—How was your friend's vacation?
— [ ]
A. She went to see her aunt
B. lt was sunny and humid
C. lt was not bad
D. She went to the beach last Sunday
表面裂纹一般产生的磁痕是（）。
A.明显而清晰
B.宽大而不清晰
C.宽阔而无明显的边缘
D.细小而模糊
