一、1. manmade 2. natural；naturally；nature
3. wonder 4. discussion 5. eastern；east 6. though
7. loud；loudly 8. opinion 9. electricity
10. below 11. shine；shone；shined；shining
12. sign 13. silent；silently 14. silver
15. sky；skies 16. grey 17. beside
18. reply；replies；replied；replying 19. clear
20. stream 21. nearly 22. remain 23. by
二、1. wonders of the world 2. natural wonder
3. in one's opinion 4. manmade wonder 5. join in
6. be sure 7. agree with sb. 8. more than
9. millions of 10. at the top 11. go through
12. walk along 13. look over 14. look across
15. fall away 16. get out of 17. in five minutes
18. on top of 19. at the bottom of 20. the other side of
21. have been to 22. be afraid of doing sth.
23. at the end of 24. faster and faster 25. dozens of
26. because of
三、1. join in 2. agree with 3. even more
4. in my opinion；more；than 5. long；high；wide
6. millions of 7. When
8. got out of；went through；walked along
9. to see 10. looked over 11. looking across
12. give a concert 13. to bury；to study
