6-14-13 Friday，library）

The gravels，the rubbles，and sands

Those gravels in a stream，

The water washed them everyday。

The sun is sunny during the day，

The moon is quiet during the night。

Year by year，

Day by day；

The gravels changed into the rubbles

Year by year

Day by day

The rubbles changed into the sands。

Who has the power to make them change？

Is water？ sun？or moon？