-I can't believe that Jeff __________ have quarreled and fought with his boss.-Well, if one __________ ask for trouble, it just can't be helped.
He __________ to the front of the crowd and wanted to see what was happening.
Tom is good at physics and likes playing basketball. __________ his elder sister.
We may __________ our past experience to develop new technology.
His health is in bad condition, and __________ he is able to work no longer.
This book __________ 18 articles, __________ three written by my father.