—Bob has gone to California.—Oh, can you tell me when he __________?
by a greater demand for green products, the food company has set higher standards to ensure the quality.
The little boy got rice to feed the chickens in the yard.
Not until all the fish died in the river how serious the problem of water pollution was.
When I was twenty, I had to before graduation and work in a clothes shop to help support my family.
After the quarrel, I tried all my best to fix the misunderstanding between us, but all my efforts seemed .