and yet children learn it so easily with minimal effort at all.而孩子们却能够轻而易举地掌握

at all完全； 根本

I assure you that you will feel no pain at all.

我保证你根本不会觉得疼的。

I don't think that's a bad idea at all.

我看这完全不是个坏主意。

how we learn to talk remains a mystery.我们如何学会讲话依旧是个未解之谜

learn to学习

I must learn to snatch at every chance to meet him.

我必须学会抓住一切机会同他见面。

A mountaineer must learn to stand the gaff.

一个登山运动员必须学会吃苦。

what makes us human and where language comes from.以及语言来自何处，我们几乎一无所知

come from来自； 起源于

We heard clink come from that room.

我们听到那个屋子传来叮当声。

He come from holland, but she come from Sweden.

他是荷兰来的，但她是瑞典来的。