flow down短语⁷⁶⁸⁶⁴ 基本例句 流下 Scientists think the best explanation for the gullies is that seasonal melting of nearby water ice creates slurries of sand and liquid water, which flow down the crater's dunes. 科学家认为这些沟壑形成的最佳原因是，附近的水冰因季节性消融而形成的沙浆及液态水流下山丘形成了这些沟壑。 yeeyan