The teacher was angry that all of them arrived late for a(an) ___ of reasons.
17. With the help of our class, Little Mike made such great progress in Chinese that he can write a 200-character ____ .
18. Deng Xiaoping was our general designer of reform and opening up to the outside world(改革开放). After he passed away, his ____were scattered over the sea.
19. Russia is a country which extends across _____ .
20. "What can I do for you?" or "May I help you?" is a pet phrase used by _____ .
21. Move a few steps, and the oil-paintings look better ______.