Just like a voyage at sea, our life journey, _____ days are limited, is full of difficulties as well as opportunities
Wenchuan Earthquake Museum has been built_____the people who died in 5·12 earthquake last year.
—How do people do bird-watching? —Sometimes they______the birds quietly, sometimes they use telescopes.
The Wolf and the Lamb _____so popular that some children went to see it for a second time.