我的作文,请问有哪些语法错误?（作文题目是What can we do to fight pollution）

题目

我的作文,请问有哪些语法错误?（作文题目是What can we do to fight pollution）
内容：What can we do to fight pollution?First,we must put the rubbish into rubbish bins.Sencond ,we mustn't use too many plastic bags.Then,we must plant more trees.We must take a bus or ride a bike or walk to school.And we must close all the lights and fans when we leave a room.We must close all the windows when we use the air-conditioner.
内容：What can we do to fight pollution?First,we must put the rubbish into rubbish bins.Sencond ,we mustn't use too many plastic bags.Then,we must plant more trees.We must take a bus or ride a bike or walk to school.And we must close all the lights and fans when we leave a room.We must close all the windows when we use the air-conditioner.Let's try our best to fight pollution!

答案

改错:
What can we do to fight pollution?First,we must put【删掉the】 rubbish into rubbish bins.【Sencond拼错了,是second】,we mustn't use too many plastic bags.【改Then为Third(这里用then不适合)】,we must plant more trees.We must 【改“take a bus or ride a bike or walk to school”为get to school either by bus,bike or on foot】.【改And为In addition或Furthermore】 we must 【改close为turn off】all the lights and fans when we leave a room.We must close all 【删掉the】 windows when we use 【改the 为an】air-conditioner.
注:"Second,we mustn't use too many plastic bags"这句话虽然没有语法错误.但是你的题目是“What can we do to fight pollution".你给的是”我们不该做什么“的答案,但是给一个”我们该做什么的“肯定句式更好些.因此,建议把这一句话改为"Second,we must reduce the amount of plastic bags we use." (我们应当减少用塑料袋的数量).
fight后面against可加可不加.