题目

Do you often run outdoors to keep healthy？Have you ever thought about how running helps to clean up the earth？Sometimes a creative mind can bring us a win-win（双赢）situation. Plogging，a new way to exercise，began in Sweden（瑞典）. The name “plogging” comes from two words-the Swedish（瑞典的）word plocka”，which means to pick up（捡起）”，and the word “jogging”，which means “to run slowly”. A Swedish man called Erik started the movement. He saw rubbish here and there when riding to work each day. He became worried about the dirty environment and dec15世纪中期灭亡拜占廷帝国的是　 A．亚历山大帝国        B．法兰克王国           C．阿拉伯帝国         D．奥斯曼帝国