Dear lucy
I am sorry to hear that you are ill now.How are you feel now? Are you better?Now the weather is getting colder and colder. You need warm clothes.Many of my classmates have a cold.They can't come to school. My teacher is sad too.They can't teach because many of my classmates stay at home.This morning, my teacher took us to run in the playground.It is good for our health.How about your school and your classmates.Please write to me.
How are you feel now应是How are you feeling now 你最近觉得如何？be + doing...
My teacher is sad too.They can't teach because many of my classmates stay at home.此句有点矛盾，前面是单数，而后面是复数，最好都改为复数。
确实这样的，天气一变好多同学感冒，同学们在注意保暖的同时，要加强自身的锻炼，多活动，多喝水，能预防感冒的。
小作者写了一篇很不错的习作，很具有现实意义，可以提醒部分同学保持好自己的身体！
