Can $ 500 _________ the cost of the whole trip?

Experiments of this kind ___in both the U．S and Europe well before the Second World War．

— The “No.1 Document” is designed to help the rural population increase their incomes.— I believe that peasants’ life ______ better and better.

Since I won the big prize, my telephone hasn't stopped ringing. People ____to ask how I am going to spend the money.

—How did it come that you damaged your car so badly? —I ____into a tree on the roadside the other day.