When I was a teenager, I felt that I was just young and uncertain --

我十几岁时，总感到自己年轻，有些事拿不准 --

This applies particularly to chemical industries,

这在化学工业方面尤其突出。

Libraries made education possible, and education in its turn added to libraries: the growth of knowledge followed a kind of compound interest law, which was greatly enhanced by the invention of printing.

藏书使教育成为可能，而教育反过来又丰富了藏书，因为知识的增长遵循着一种“滚雪球”的规律。印刷术的发明又大大提高了知识增长的速度。

that a series of deep soundings was obtained in the Atlantic and the first samples were collected by dredging the bottom.

才在大西洋测得一个个海水深度，同时通过挖掘海底，取得了研究海底的首批样品。

therefore the jungles and the savannahs know of no'juvenile delinquency'.

因此，丛林和荒凉地区不知道什么叫青少年犯罪"。

They have a character, perhaps two;

他们心中有一个或两个角色。