By the help of microscopes, there is nothing so small as to escape our inquiry; hence there is a new visible world discovered to the understanding.

童年时期注意力的发展是自我调节和学业成就的基础。

What worries you, masters you.

恐惧是迷信的主要根源，也是残酷的主要根源之一。战胜恐惧是智慧的开端。