A teacher's________to the cause of education is worth great respect of the whole society because it brings countless benefits to the development of society.
Be sure to go to the concert with me, _____?
_____ has already been pointed out, grammar is not a set of dead rules.
.---There is a lot of smoke coming out of the teaching building. ---Really? It _____be a fire, most probably.
–Did you find your new dictionary? ---Yes. I found it ____I had left it.
–Will you ______me ____out this problem myself? ---OK.