146. The family is a co-operative enterprise for which it is difficult to lay down rules, because each family, needs to work out its own ways for solving its own problems.

146、家庭就像是一個合作式的企業一樣，很難制定統一的規則，因為每個家庭都需要自己的獨特的解決問題的辦法。

147. Besides serving the indefinite needs of its native speakers, English is a language in which some of important works in science, technology, and other fields are being produced, and not always by native speakers.

147、除了以英語為母語的人大量地使用英語外，很多重要的科學、技術文獻也是由英語寫成，而且作者不僅僅是以英語為母語的人。

148. And someone with a history of doing more rather than less will go into old age more cognitively sound than someone who has not had an active mind.

148、比起那些頭腦不活躍的人來說，年輕時喜歡盡量從事更多工作的人年老后更有認識力。

149. Perfectionists struggle over little things at the cost of something larger they work toward.

149、完美主義者傾向于為了一點小事花費比事情本身更大的代價去完成。

150. Men are naturally most impressed by diseases which have obvious signs, yet some of their worst enemies slowly approach them unnoticed.

150、人類自然地對于那些有明顯特征的疾病有深刻的印象，然而他們最可怕的敵人往往在未被人注意時慢慢接近他們。