21. — We must teach our children to be polite to ________ elderly.
— Yes. They should learn to treat others in ________ more polite way.
A. an; a B. the; a C. the; an D. an; the
22. — What a thick fog! I went the wrong way at the corner and finally got lost.
— It's easy to make a wrong turn here even under an ideal weather ________.
A. conversation B. conclusion
C. condition D. communication
23. — I'd like to travel to Moscow for vacation.
— Get real! For our poor situation at present, we can't ________ a vacation.
A. accept B. afford C. offer D. provide
24. — Mum, I hear something terrible outside in the garden.
— Don't be afraid, baby. It is just the rain beating ________ the windows.
A. through B. against C. across D. above
25. I'm afraid that this type of energy will ________ if we continue to waste it.
A. run out B. break out C. come down D. fall down
26. — Mary, it's really nice to see you again. Where have you ________?
— I ________ a school in a mountain area for two years.
A. gone; have been to B. been; have been to
C. gone; have been in D. been; have been in
