—I am sorry to have __ too much of your time. —That's OK, and I am glad to help you.
They stopped at Tianjing_____they might visit the TV tower.
She has _____she remembers all the names of the students she has taught.
It is_____ all of us can do it.
The house cost_____ we didn’t buy it.
The book is_____ it gives a wrong idea of the facts.