干眼病（）
A.维生素B1缺乏
B.核黄素缺乏
C.维生素A缺乏
D.维生素C缺乏
E.烟酸缺乏
参考答案：C
—Guess what! Alice has failed in the exam.
— ____? She is second to none in English in our class. [ ]
A. How is it
B. How come
C. What
D. What is it
站内线间设有高柱信号机时，相邻两线（含正线）均需通行超限货物列车，线间最小距离为多少mm？
