Our hearts sank at the news that a pipeline(输油管) ______in Qindao and 62 people couldn’t survive the disaster.
After the long journey, the Smiths returned home, ____.
Not everyone has realized what_______ important part the balance of________ nature plays in their life.
It’s easier to catch a _____ lion than the one that’s awake.
Mr. Smith didn’t go to the party because he had a lot of experiments _____.
Only if he gets a job ______ have enough money to build his own house.