She is always thinking more of herself, seldom, ________, offering to help others.
17. _______ here in time, he came _______ all the way.
16. After he left college, he was employed in an international company and _______ there ever since.
15. The factory _______ large numbers of tractors to the peasants.
14. The teacher insisted _______ until we finished the work.
13. — How do you keep fit? — By having a healthy diet and _________ regularly.