I hope to see Niagara Falls one day. What about going there- Niagara Falls would be beautiful, but there is not much to do there.

Clean water and fresh air are essential for our daily life, _______ we can’t live.

“Don’t talk in class again ”, the teacher said to him .The teacher ________.

What about taking a walk after dinner —______________.

My friend Tom _______me __________ for an houryesterday.