教育学是研究人类（），揭示（）的一门科学。
参考答案：教育现象；教育规律
My dictionary______ . I have looked for it everywhere but still _____ it. [ ]
A. has lost; don't find
B. is missing; don't find
C. has lost; haven't found
D. is missing; haven't found
货物列车距离分相点（）、500m时，LKJ语音提示“禁止双弓”。
A.1000m
B.1500m
C.2000m
D.1200m
