1. Can be achieved by a brief period lying, or even sitting down.
    只要稍微躺一躺，甚至坐一坐就能达到。

2. But a closer study of the evidence, supported by a deeper sense of the period, and particularly by a new consciousness of the philosophical undercurrents in the scientific revolution, has profoundly modified this view of Galileo.
    但是，对那个时代的深化了解，尤其是以科学家革命中哲学潜流的新意识为依据，进一步仔细研究，就会极大地改变对伽利略的看法。

3. But it was still too short a period for men to base a calendar on.
    但时间依然太短，人们无法以此为据制定历法。

4. But with such a large population base, the country must still convert millions more to the idea of birth control if it is to reach its population targets.
    但是因为该国的人口基数十分大，要想达到政府的人口目标，印尼还必须再转变几百万人的思想，让他们接受节制生育的观念。

5. When research into cloning is resumed, human cloning should remain a research activity for an extended period.
    当克隆研究重新开始时，克隆人类应该仍然是一项历时长久的研究活动。

6. To betray a friend is a base action.
    出卖朋友是最卑鄙的。

7. The Qin dynasty existed for a very short period.
    秦朝存在的时间很短。

8. Two days later a message came in from the North Carolina Marine Corps base informing the Brooklyn Red Cross that the real son was on his way to Brooklyn for his father's funeral.
    两天后，北卡罗来纳海军陆战队基地给布鲁克林红十字会发来一份通知：真正的儿子正在来布鲁克林参加父亲葬礼的路上。

9. The period following the Civil War said "Get set!";
    内战后的那段时期说"预备！

10. He could not have had a better mentor during this very trying period.
    在这艰难的时刻他不可能找到比这位更好的老师了。