这次不用苦思冥想了吧?
It was quietly floated ... --> It was quitely floating ...?
or --> It floated quietly ...?
only the rivers drew curly black lines -- It appears that there is only one river?
只有河流在美丽的画面上划出一道曲曲弯弯的黑线, here 一道 not 一道道 ?
Just my two cents.