[解析]
(1)C.细节理解题.根据"Schools around the Chicago area have adopted CrossFit to interest students at a time of a rising weight problem among young people"可知在芝加哥地区采用CrossFit帮助解决学生的体重问题.故选C.
(2)A.细节理解题.根据"and most say it really works compared with traditional gym classes."可知大多数人认为力量训练是有效的.故选A.
(3)C.推理判断题.根据"Senior Alexus Wiltz,18,said the workout had improved her performance on the basketball court."可知"workout"指的是"体育锻炼".故选C.
(4)D.细节理解题.根据"Gym teachers in Waukegan's Greg Moisio,whose two﹣campus school has about 73%kids taking CrossFit each day,also say the risk of injury can be reduced with proper teaching and CrossFit's flexibility"可知从最后一段我们能学到如果孩子训练得当,他们可以保护自己.故选D.