The companies are working together to creat ______ they hope will be the best means of transport in the 21st century.
23. Everyone should remember it is very important to _____ the balance of nature toady.
22. She always ____ her opinion ____ facts.
21. Every morning, the fish mongers stood there ______ with the fishermen for fishes.
20. When Jack arrived, he learned Mary ____ for almost an hour.
19. They didn't _____ the wedding because of a heavy rain.