The phrase "a drop in the ocean" is pronounced as:

/ə drɒp ɪn ði ˈəʊʃən/

In terms of translation:

中文翻译：沧海一粟，微不足道的事物，指非常小或微不足道的部分。

This phrase is often used metaphorically to express that something is a very small and insignificant part of a much larger whole.