To be a scientist, I can help the human beings solve a large number of tough problems in certain field, as for me, it is a great cause, bringing me a sense of accomplishment.

成为一个科学家，我可以帮助人类解决在某些领域解决大量艰难的问题，对我来说，这是一项伟大的事业，给我一种成就感。

youdao

A number of genetic defects of the sensory organs is connected to certain colours and patterns, because of problems with this migration.

一些感观器官的基因缺陷与某些颜色和形式相联系，正是因为其输送过程中出错了。

youdao

There are a number of factors that can affect fertility, and ai is better suited to certain problems rather than others.

有一些因素会影响生育，和AI是更适合的某些问题，而不是别人。

youdao

"One of the programming problems was try to figure out how to break an arbitrary chocolate bar into a certain number of pieces of a certain number of sizes and to do it as quickly as possible.

VOA: special.2010.03.11