It's our duty to ___

It's our duty to make our city much_____ it's our duty to protect our environment/是什么意思请问 it's our duty to help ____(protect)the environment it's our duty ti distribute to the society It's our duty to ____ _____ _______（保护环境） it's our duty to fight___this kind of terrible disease. It's ___ ___ ___ ___ our classroom and duty.(保持教室干净整洁是我们的责任. I think it's our duty to keep our environment clean and tidy Don't throw waste paper everywhere.It's our duty to keep our It's our duty to take good care of our ________(环境).主要是要不要用复 Don't t_____ here and there.It's our duty to keep our school Waste paper shouldn‘t everywhere.It‘s our duty to keep our c