let's stop__ to keep the earth beautiful and clean.pollute)

let's stop__ to keep the earth beautiful and clean.pollute) we must s______ the earth and keep it clean and beautiful He wants to travel around the world and keep the earth clean We must keep the air clean and never _________ (pollute,poll 英语The important thing is to keep the earth clean. we must keep sea water clean and stop___it(pollute) Stop__(talk)and let's begin our lesson 填同音词Let's go to（）the（ ）.It's very big and beautiful. Friends of the Earth help keep the environment clean.“ keep let's help to pick up the litter and keep the park c_____ ag What do yoy promise __(do) to keep the earth clean. chairs,the,clean,desks,and,let's 整理成句