________ got on the train when it began to move.
—Dad, when shall we go to visit my grandpa? —Grandpa is very busy at present.We'll go to see him whenever __________.
Do you think the idea he stuck ____correct?
The hungry man eats his food _______he hadn ' t eaten for a week.
We must ________ our task, however hard it is.
________ the same mistake again made his parents very angry.