列车到达前，道口工应检查哪些设备？
参考答案：1.检查道口铺面；
2.轮缘槽是否完好；
3.线路有无影响行车安全的障碍。
It is reported that two schools, ___ are being built in my hometown, will open next year.[ ]
A. they both
B. both of them
C. which both
D. both of which
缩窄性心包炎最具特异性的体征是（）
A.心包叩击音
B.奇脉
C.颈静脉怒张
D.水肿
E.肝大
