a cold front的用法和样例：
- A cold front is moving in from the north.
- A cold front is the forward edge of a mass of moving cold air.
- The radio says a cold front is coming, with strong winds from the northwest. The highest temperature during the day will be two degrees centigrade.
- The weather forecast shows a cold front across the area.
- According to the forecast,a cold front is moving towards this region.
a cold front的相关资料：