在该世纪后期，科学家和技术人员开始研究烟花的实际用途，比如利用烟花帮助水手确定他们在海上的位置。
Later in the century scientists and technicians started to look at the practical purposes for which fireworks might be employed, such as using rockets to help sailors establish their position at sea.
她说，研究结果仍然表明，从那些不够突出的推荐信开始，女性在地球科学领域工作的职业生涯的一开始就处于潜在的不利位置。
She says the results still suggest women in geoscience are at a potential disadvantage from the very beginning of their careers starting with those less than outstanding letters of recommendation.
在一次海上航行开始之前，谨慎的航海家们会研究海图，了解航海方向，还要记住灯塔的位置，以保证当遇到任何困境时他们都有所准备。
Before starting on a sea voyage, prudent navigators learn the sea charts, study the sailing directions, and memorize lighthouse locations to prepare themselves for any conditions they might encounter.
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