John: What do you do on Sundays?
Tom: I read books and watch TV. What do you do on Sundays?
John: I do my homework . What about you, Mary?
Mary: I clean my room and watch TV.
John: You're helpful.
下图为某时赤道南北天气状况示意图(单位:百帕),下图中正确反映①锋面过境期间,g地温度变化过程的是( )