Which human activity can have a negative impact on the stability of a mature ecosystem? A)
preserving natural wetlands, such as swamps, to reduce flooding after heavy rainfalls
B)
replanting trees in areas where forests have been cut down for lumber
C)
building dams to control the flow of water in rivers, in order to produce electricity
D)
passing laws that limit the dumping of pollutants in forests

C, i'm pretty sure but plsss help me

ASAP

Amelia had 28 sea shells. Then, she collected 10 more sea shells. After that, she gave S sea shells to her little sister. Which of the following shows how many sea shells she has currently?

A.  28 - 10 - S

B.  28 + S - 10

C.  28 + S + 10

D.  28 + 10 - S

yes i have all the correct answers

1. c 6. b. 11. c

2. a 7. d. 12. d

3. c 8. b. 13. c

4. d 9. c. 14. d

5. c 10. d. 15. a

16. d. 21. a

17. d.

18. a. 22-30 you must do on

19. d. your own

20. d.

segmentation=endoskeleton=backbone=coelom=tissues