For most people the sea was remote and with the exception of early intercontinental travellers or others who earned a living from the sea ,there was little reason to ask many questions about it , let alone to ask what lay beneath the surface.

remote ad. 遥远的 intercontinental 两个相连接的大陆

earned a linving 谋生 let alone 更不用说

The first time that the question‘what is at the bottom of the oceans ?\' had ti be answered with any commercial consequence was when the laying of a telegraph cable from Europe to America was proposed.

commercial consequence 商业价值

Normally a student must attend a certain number of courses in order to graduate , and each course which he ateends gives him a credit which he may count towards a degree.

credit 学分

A student who has held one of these postions of authority is much respected and it will be of benefit to him later in his career.

authority career
n.当局，官方；权力 n.生涯，职业，经历

Psychologists take opposing views of how external rewards , from warm praise to cold cash ,affect motivation and creativity.

external adj.外部的，外面的 motivation n.行为的动机

creativity 创造力

A teacher who continually diaws attention to rewards or who hands out hingh grades for ordinary achievement ends up with uninspired students , Eisenberger holds.

ordinary adj.普通的