If we throw away too much waste and can’t keep good ecosystem,we _________ our future.
Scientists are convinced______ the positive effect of laughter______ physical and mental health.
The prize will go to the writer______ story shows the most imagination.
If we sit near____ front of the bus , we’ll have______ better view.
---Do you need more beef steak? ---______.
They _____ have arrived at lunch time but the flight was delayed.