A greenhouse is a ____46_____ made of glass that allows sunlight to enter hut ______47______ heat inside, so the building stays warm even when it's cold outside. _______48________ gases in the Earth's atmosphere also let in light but trap heat, many people call this phenomenon the “greenhouse effect/' If it were not for greenhouse gases trapping heat in the atmosphere， the Earth would be a very cold place. The Earth gets energy from the sun in the form of sunlight. The Earth's surface ________49________ some of this energy and heats up. That’s why the surface of a road can feel hot even after the sun has gone down. The Earth cools down by giving off a different form of energy, ________50_______ infrared radiation. Before all this radiation can cscape to outer space，greenhouse gases in the atmosphere absorb some of it, which makes thie atompsphere warmer,As the atmosphere gets warmer, it makes the Earth's surface warrheh ,too. 

      As your train follows the North Link Railway along the eastern coast of Taiwan, you will see high mountains on one side and blue sea on the other in an enchanting picture of natural wonder. Along the way you will enjoy viewing the changes of nature's handiwork. After the train rolls onto the Lanyang Plain, your eyes will be filled with bright green rice paddy and, in the distance, the Turtle Island, majestic mountains and deep blue waters.

      Besides scenic spots, you can also enjoy a vast range of tribal attractions in the Hualien and Taitung areas. It is well known that eastern Taiwan has the highest concentration of aboriginal tribes ( Amis, Puyuma, Atayal, Rukai and Bunun ). Tourists may join a variety of tribal celebrations staged in Hualien, and the Amis Harvest Festival is the best known. Each Amis village holds its own festival that lasts for an average of three days in mid-July for Taitung villages, and in August for Hualien villages. Late in the year, usually in December, Puyuma villages hold the Monkey Festival in which males of the tribe --in the past-- killed a monkey as part of young braves' initiation into manhood. 

    According to the aboriginal language, the tribal name Puyuma means “ together ” and “ united ”. The Taiwan Railway Administration introduced a new tilting train, “ Puyuma Express ” (普悠瑪), which was named after the aboriginal tribe in Taitung County. In response to public expectations, the Puyuma Express started service along the eastern coast in early 2013.