假定英语课上老师要求同桌之间交换修改作文，请你修改同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。
增加：在缺词处加一个漏字符号（∧），并在其下面写出该加的词。
删除：把多余的词用斜线（\）划掉。
修改：在错的词下划一横线，并在该词下面写出修改后的词。
注意：1）每处错误及其修改均仅限一词；
2）只允许修改10处，多者（从第11处起）不计分。
Dear Sir,
I'm writing to offer some advices on our winter travel. In my opinion, a one-week trip to a countryside can't be good. The fresh air and various activities will guarantee us a healthy life here.
We may go by bike to enjoy the landscape. During the trip, we can arrange some activities, from what we will benefit a lot, such as playing snowballs, building a snowman, going skating and climb a mountain. We can even invite the local students join us, not only to improve their English but also to deepen their understanding of the countryside. I am confident to establish friendship and harvest happy from this trip.
I would appreciate it that if you could take my plan into consideration.
