How often do I need to feed the birds?—They ________ food every day，or they will behungry.

You can help your body by drinking water when you’re thirsty _____drinking extra water when it’s warm out[ ]

By the time Jack returned home from England, his son _____from college. [ ]

Mr Black told us that the only way to conquer English is to practice __________[ ]

is reported in the newspaper is that seventeen climbers have been killed in the snow storm