-----Have you seen___ pen? I left it here this morning. -----Is it __black one? I found it in the corner.
—Sorry, I have to __________ now. It's time for class. —OK, I'll call back later.
(2009·北京) For breakfast he only drinks juice from fresh fruit __________ on his own farm.
After that, he knew he could __________ any emergency by doing what he could to the best of his ability.
Never before __________ seen anybody who can play tennis as well as Robert.
Only with the greatest of luck __________ to escape from the rising flood waters.