287. The clear colorless liquid that falls as rain, fills lake and rivers, and is necessary for life to exist is______.
Great changes ______ in China in the past 20 years.
His illness his absence.
When the man was trying to break into the bank, he was caught by the police.
My best friend who _______ a rich man two years ago has a baby now.
It snowed heavily; ______, lots of flights have been put off until further notice.