C．more calories and fat will result in serious illnesses

　　D．speed walking can effectively cure kinds of diseases

　　解析：选C　推理判断题。依据第四段的第二句可知，快走有助于燃烧脂肪；依据尾句可知，快走会帮助改变我们的生活方式，有助于抵抗糖尿病、肥胖和其他疾病。由此可推知，过多的热量和脂肪会导致疾病发生。

　　3．What does the underlined part "hold water" mean?

　　A．Have a drink.　　　　 　B．Make sense.

　　C．Work out. D．Build up.

　　解析：选B　词义猜测题。依据下文可知，不管多大年龄的人，在快走几个月后就会看到快走的益处。因此此处指那些人说自己太老太胖而不能快走是没有意义的。

　　B

　　Most of us are familiar with the "Silk Road"， a network of land trading routes which connected northwestern China to Europe since the Han dynasty.With its recent popularity, you may have heard of the "Tea Horse Road" as well, another network of land trading routes that also connected China to various parts of Asia and Europe before sailing became common.Historically, the "Tea Horse Road" is no less important than the "Silk Road"， and because of their different locations, the "Tea Horse Road" is sometimes referred to as "the Southern Silk Road"．

　　The "Tea Horse Road" has got its name as Chinese tea and horses were the main products traded along the route (together with medicine, salt, cloth and skins)．Historians have traced the origins of the "Tea Horse Road" back to the Tang dynasty, when tea was being transported out of Yunnan to Beijing, Tibet, and other Southeast Asian countries.The "Tea Horse Road" was further developed during the Song and Ming dynasty, and remained a key trading route for Pu'er tea and other goods until the Qing dynasty.

　　Like the "Silk Road"， the "Tea Horse Road" was not a "road" by itself, but a network of routes spreading out of Yunnan's Pu'er County.In its more than 1,200 years of history, the "Tea Horse Road" served not only as a trading route, but also a bridge connecting different races (种族) - politically, economically and culturally.

　　Today, the "Tea Horse Road" is a hot spot for tourists.History aside, the "Tea Horse Road" is located near "The Third Pole of the Earth" and "The Roof of the Earth"， making it a spot of many attractions.

　　语篇解读：本文是说明文。茶马古道是指存在于中国西南地区的民间国际商贸通道，是中国西南民族经济文化交流的走廊，也是早期沟通中国西南地区和亚欧商贸的重要通道。

　　4．What do we know about the "Tea Horse Road"？

　　A．It dates back to the Tang dynasty.

B．It was built earlier than the "Silk Road"．