Choose A, B, C, D to complete the paragraph

Choose A, B, C, D to complete the paragraph. 
These days it is important to open a newspaper (21)______ reading about the damage we are doing to the environment. The earth 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 plan 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 a 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. without         C. and            D. but
22. A. and            B. however        C. so            D. moreover
23. A. Where            B. When        C. Why            D. What
24. A. up             B. to             C. on            D. in
25. A. appear            B. appearance        C. disappear        D. disappearance
26. A. when            B. during        C. while        D. within
27. A. complete        B. completeness    C. completely        D. to complete
28. A. water            B. energy        C. money        D. health
29. A. adds            B. decreases        C. reduces        D. supplies
30. A. from            B. for            C. to            D. in