My father waved me good bye and the bus set off. The person sitting next to me was a government engineer going to Peshawar to inspect the roads. He said that traveling by bus was an excellent way to test the roads. We 76____ many villages on the wa

My father waved me good bye and the bus set off. The person sitting next to me was a government engineer going to Peshawar to inspect the roads. He said that traveling by bus was an excellent way to test the roads. We 76____ many villages on the way and stopped once or twice to buy cold drinks, because it was very hot and dusty. The countryside was brown and dry and there were long stretches with no people or villages 77____ sight. We had to stop once at some road works, too, which made my traveling companion very 78____ .
Most of us were dozing in the afternoon heat when we were 79____ by a sudden noise, which sounded like a 80____ from a gun. As the bus swerved and then stopped at the side of the road, I remembered all the 81____ I had heard about bands of robbers who 82____ attack travelers on deserted roads like this. Many of the other passengers looked as bewildered and frightened as I must have looked.
My 83____ , however, reassured me: “Nothing to worry about. Only a 84____ tyre. But we shall have to wait 85____ he changes the wheel.” My cousin Anwar met me at the bus station. “Well, there you are,” he said. “I was beginning to wonder what had happened to you.”85____

A. while

B. before

C. until

D. unless

正确答案是A