He wants to travel around the world and keep the earth clean.后面为什么不是 to keep
问题描述：
He wants to travel around the world and keep the earth clean.后面为什么不是 to keep
He usually takes photos and looks after plants.后面looks为什么是三单?
答
1.He wants to do two things:travel around the world and keep the earth clean.相当于：He wants to travel around the world and (to) keep the earth clean.keep 与travel平行,跟在wants 后面,第二个to 省略2....那加to错吗不错，但一般不加