However hard I tried, I just couldn’t ________ them of the truth of my story.

did you take swimming classes last term — Once every two weeks.

d himself behind the door, _________ he couldhear the steps of his mother clearly

Let’s go out for a walk.—You’d better not. These days the air is getting much ________ than it was before.

Oh, it’s you, I’m sorry I ____know you ____here