驾驶机动车通过这个铁路道口时要减速停车。
参考答案：对
解析：如图，红灯亮了，控制杆也要落下来了，说明火车马上要开过来了，要减速停车。
It was not until 3 days later that the boy came back to life and explained to the police what_______ to him.
A．was happening
B．was to happen
C．had happened
D．has happened
色盲片只感受（）光？
A、红
B、绿
C、黄
D、蓝紫
