我国是世界上稀土资源最丰富的国家，有"稀土王国"之称,但稀土资源的利用率不到10%。稀土矿产资源的消耗速度加快，要解决这个问题，关键是（    ）

下图是一个直角三角形(单位：厘米)．用两个这样的三角形可以拼成一个等腰三角形．要使拼成的等腰三角形周长最大，可以怎样拼？画出示意图，并算出拼成的等腰三角形的周长．

根据短文理解，选择正确答案填空。 

    Jim is a junior high school student. He gets up 16:30 every morning. His home is near his school. He 2home after breakfast. He goes to school on foot. This is good for his 3. He has four lessons in the morning. He has lunch at home. After lunch he goes to school again. In the afternoon, Jim has lessons . He likes English and PE lessons. He has PE lessons on Tuesday and Friday. He is good at4football and basketball. He is also good at the high jump. His PE teacher likes5 very much. He often plays football with his classmates after school.