铁路专用通信是直接为（）服务的重要（）设施。
参考答案：铁路运输生产；通信
The traffic rule says young children under the age of four and less than 40 pounds must be in a child safety seat.
A．being weighed
B．to weigh
C．weighed
D．weighing
It was in the university ten years ago, _________ they met in September for the first time, _________ they fell in love with each other.
A．that; when
B．when; that
C．that; where
D．where; that
