题目

“一只乌龟”、“湘江里的所有鲤鱼”分别属于生命系统中的哪个层次（） A . 种群、个体 B . 个体、种群 C . 个体、群落 D . 细胞、种群 答案：B You must know the “ding dong ditch”. Person A rings Person B’s doorbell, and then quickly runs away or hides before Person B answers. Person B hurries to answer the door, only to find that on one’s there. After the __16__ thing is repeated several times, this is called “ding dong ditch”.     Sharon Mardis, a single mother of four, told ABC(Australian Broadcasting Corporation) News that she __17__ a “ding dong ditch” when she __18___ to her door at 1:00 a.m. last night.     “My doorbell started ringing, and I came to the door,” Sharon told ABC News. “There was nobody at the door. I went back in the house. I got ten to twenty feet and the doorbell started ringing again. I came back to the door, but there was still nobody at the door.” She got __19__ and stepped outside, shouting, “Who’s that? What on earth are you going to do?” Everywhere seemed to be __20__.     But after Sharon returned to the house, she __21___ something. Smoke! Sharon quickly __22__ her kids and the family pets and ran out of the house. Only then did she __23__ how bad the fire was. The __24__ of the house fell down; the house was quickly covered by __25__ . The smoke detectors （探测器）had never gone off; they were out of batteries. Good thing for the doorbell.     The __26__ is who had rung it. __27__ found that the flames had fused （溶化）the wires of the doorbell together, causing it to ring. But __28__, the fire had nothing to do with the door wiring at all. It had started in the bathroom, well down the hall. From there, the flames didn’t spread to the nearby __29__, where the children and Sharon were sleeping. Instead, they surprisingly reached the doorbell first, making it ring repeatedly, and __30__ Sharon to avoid danger.     Sharon believes it happened that way thanks to an angel. 16. A. special B. same C. important D. serious 17. A. experienced B. followed C. learned D. practiced 18. A. fell B. turned C. responded D. returned 19. A. angry B. tired C. worried D. interested 20. A. awful B. dirty C. silent D. funny 21. A. tasted B. felt C. touched D. smelled 22. A. comforted B. settled C. gathered D. frightened 23. A. realize B. dream C. wonder D. agree 24. A. paintings B. roof C. lights D. floor 25. A. clouds B. sands C. trees D. flames 26. A. question B. opinion C. mistake D. fact 27. A. Nurses B. Teachers C. Firefighters D. Doctors 28. A. fortunately B. strangely C. honestly D. clearly 29. A. kitchen B. hall C. bathroom D. bedroom 30. A. ordering B. encouraging C. warning D. advising