25.
(A) encourage
(B) encouraged
(C) are encouraged
(D) have encouraged

21. Husband: I’m exhausted!____________ Wife: But it helps protect the environment. Husband: I know. Are there easier ways of doing it? It takes too much time to classify things. Plastic bottles in this bag, regular garbage in that one…. It drives me crazy. Wife: Why don’t you take a break? I’ll take care of it. (A) We have only one earth. (B) Clean air is what we need now. (C) I think recycling is just a waste of time. (D) Environmental protection is really important.

22. (A) above (B) at (C) over (D) up

23. (A) Because (B) If (C) Unless (D) While

24. (A) become (B) becomes (C) to become (D) will become

26. (A) ease (B) easy (C) easier (D) easily

27. (A) back (B) down (C) out (D) up

28. (A) Before (B) For (C) On (D) Since

29. (A) intense (B) effortless (C) identical (D) eager

30. (A) had better (B) used to (C) ought to (D) would rather

31. (A) get (B) gets (C) to get (D) getting