?? 詞語組成解析
n. 內(nèi)卡河（德國西南部河流）
river
['riv?]
n. 河，江;溪，巨流;
??? 情景例句
What are you working on?
你在做什么？
To walk on a beautiful day
在晴朗的日子出去散步
It was from the study of these that so much was learnt about the interior of the earth.
正是從這兩種波的研究中，我們可以了解到地球內(nèi)部的許多情況。