Scientists say it may be fiveyears ______ it is possible to test this medicine on human patients．

The total cost of their trip to Canada_____$ 8,000.

She was so sad because she failed in themath test. Let’s ______ her _______.

_____ I catch a cold, I have pain in my back

Many people believe that hunger is only a problem in the developing countries.________，it is a problem all over the world.