h is being threatened (22)..the future looks bad. (23)…can each of us do? We cannot clean (24)…… our polluted rivers and seas overnight, nor can we stop the (25) …. of plants and animals. But we can stop adding to the problem (26) …. scientists look for answers. It may not be easy to change your lifestyle (27) …… But some steps are easy to take: cut down the amount of driving you do, or use as little plastic as possible. It is also easy to save (28) …, which also (29)……household bills. We must all make a personal decision to work for the future of our planet if we want to ensure a better world (30)…….. our grandchildren. 21. A. with B. but C. and D. without 22 A. so B. and C. moreover D. however 23. A. What B. Where C. When D. Why 24. A. to B. up C. on D. in 25. A. appear B. disappearance C. appearance D. disappear 2 / 2 26. A. while B. when C. within D. during 27. A. complete B. completeness C. completely D. to complete 28. A. energy B. money C. health D. water 29. A. supplies B. adds C. decreases D. reduces 30. A. from B. to C. in D. for