太阳能列车接近无线报警器、列车接近与作业图像监控器、道口广播是有人看守道口必须配置的道口设备。（）
参考答案：错
循环冷却水系统在日常运行中水质有哪些变化？
If he ______ more carefully, that accident _______ and he _______ .[ ]
A. were driving; wouldn’t happen; wouldn’t die
B. had driven; wouldn’t have happened; wouldn’t die
C. had driven; wouldn’t have happened; wouldn’t have died
D. should have driven; wouldn’t have been happened; wouldn’t have died
