浇花过勤，土壤含有大量水分，往往植物的根会腐烂、死亡，其原因是（ ）
A．土壤溶液浓度过高，根毛无法吸水
B．水分过多，使细菌大量繁殖
C．水分过多，根无法呼吸
D．根吸水过多，使根的细胞胀破
植物的根呼吸的是空气中的氧气．经常松土，可以使土壤疏松，土壤缝隙中的空气增多，有利于根的呼吸，促进根的生长．浇花过勤，花土总是含有大量的水分，水把土壤缝隙中的空气排挤出来了，使土壤中的氧气过少，根毛无法呼吸，导致烂根，使植物死亡．
故选C
Ling Ruiming has long dreamed of traveling around the world. But when the 86-year-old man was diagnosed with terminal cancer, it 48 that his dream would never come true. 49 a micro blog his granddaughter Ling Yifan posted on Sina Weibo, China’s Twitter-like platform, Ling Ruiming was able to travel around the world within several days. “My grandpa is sick with few days 50 ,” she wrote. “All he wanted to do is to travel around the world. Could you please do him a favor of taking him around the world by taking a photo with his 51 at your place?” Within three hours, the post was forwarded (转发) tens of thousands of times. Ling Yifan has 52 more than 20,000 replies with photos of her grandfather’s portrait at places around the world, including the River Thames in England and the Berlin Wall in Germany, even a picture at the South Pole. Her grandfather was delighted and grateful to see his photo 53 different backgrounds from all over the world. Ling Yifan said, “It was not until three months ago, when my grandfather was diagnosed and moved to Peking University Third Hospital, that I realized the love between family members is the most precious and 54 part of life. What I did is just my way to fulfill the grandpa’s dream and 55 some of his regrets.”
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