小东发现骑摩托车的人到了寒冬时节常常车座上垫上一块海绵做的垫子，而到了夏天常常车座上垫上一块竹子做的垫子．骑车人为什么要这么做呢？小东猜想：这是不是因为海绵和竹子的物理特性有什么不同呢？

（1）请你根据情景提出合理的猜想．

（2）设计一个实验检验你的猜想．要求写出实验方法．

The famous orchestra, which was composed by the two young musicians , is _______ into four parts according to the folk songs .

A．picked up

B．given up

C．turned up

D．split up