We were pleased to hear from your letter of 6 August that you were impressed with our selection of toys.
我们很高兴收到你方8月6日来函得知你方对我们的玩具非常感兴趣。
is as the proportion of the total vocabulary of his mother tongue against those words of his own baby talk that are taken up into the vernacular of his family.
就好像他本国语言的总词汇量和自己咿呀学语时他家庭所接纳的他的词汇量之比。