完形填空。 I can't remember when I started collecting litter. But it was when I got tired of (1)_____ litter nearby and realized that (2)_____ was going to pick it up. I live near a (3)_____ in Enshi, Hubei Province. I can walk there in three (4)_____! I (5)_____ love going there to play with my dog. But one day there was so much litter there that I became very unhappy. I decided I had to clean up the forest. I wanted to (6)_____ happy going there again. I made my (7)_____ trip to clean the forest that afternoon. I took a big black rubbish bag with me. Ten minutes (8)_____ starting to pick up litter, my bag was full! It had cans, bottles, broken glass and newspapers in it. From then on, I went to the forest four times a year to pick up the litter. I often (9)_____ there for three hours. It makes me feel (10)_____ to do something for the environment. After each trip, I (11)_____ all the litter that I've found. If (12)_____ of it is recyclable (可回收的), I keep it. I can't (13)_____ why people drop litter. But I will keep picking it (14)_____ they stop dropping it. I know I am only doing a small bit to help (15)_____, but I still think it is important. (     )1. A. see (     )2. A. no one else (     )3. A. school (     )4. A. months (     )5. A. would (     )6. A. look (     )7. A. first (     )8. A. after (     )9. A. play (     )10. A. worried (     )11. A. bury (     )12. A. many (     )13. A. wonder (     )14. A. until (     )15. A. myself B. seeing B. I B. forest B. hours B. do B. feel B. third B. later B. go B. sad B. burn B. little B. ask B. as B. the earth C. look C. everyone C. river C. days C. am used to C. make C. fourth C. before C. work C. disappointed C. sell C. any C. hope C. after C. other D. looking D. anyone D. park D. minutes D. used to D. see D. fifth D. of D. sit D. great D. look at D. much D. understand D. when D. the litter