上星期天，我们拜访了这位老科学家。

Last Sunday we called on the old scientist.

youdao

从前有一个老科学家，他写了许多文章。

There once lived an old scientist who wrote many articles.

youdao

当老科学家在谈天空的蓝色时，云团蜂拥而至。

When senior scientists talk blue sky, the clouds are about to roll in.

youdao