都很简单的题目1. Ben has four more than twice as many CDs as Jack . If they have a total of 31 CDs , how many CDs does Jack have ?Ben 的CD是Jack的2倍还多4张，如果他们一共有31张CD，那问Jack有几张CD？x+2x+4=31 ===> x = 92. Jack wants to replace the flooring in his rectangular Kitchen . He calculates the area of the floor to be 12.8 square meters , The act...
