In every cultivated language there are two great classes of words which, taken together, c

omprise the whole vocabulary. First, there are those words【C1】______which we become acquainted in daily conversation, which we【C2】______, that is to say, from the【C3】______of our own family and from our familiar associates, and【C4】______we should know and use【C5】______we could not read or write. They【C6】______the common things of life, and are the stock in trade (惯用手法) of all who【C7】______the language. Such words may be called "popular," since they belong to the people【C8】______and are not the exclusive【C9】______of a limited class.

On the other hand, our language【C10】______a multitude of words which are comparatively【C11】______used in ordinary conversation. Their meanings are known to every educated person, but there is little【C12】______to use them at home or in the market-place. Our【C13】______acquaintance with them comes not from our mother's【C14】______or from the talk of our schoolmates,【C15】______from books that we read, lectures that we【C16】______, or the more formal conversation of【C17】______educated speakers who are discussing some particular【C18】______ in a style. appropriately elevated above the habitual【C19】______of everyday life. Such words are called "learned," and the【C20】______ between them and "popular" words is of great importance to a right understanding of linguistic (语言学的) process.

【C1】

A．at

B．with

C．by

D．through