相对于慈善机构的整体资金需求，他的小额捐款只是沧海一粟。

His small donation was ___a ___drop ___in ___the ___ocean compared to the charity's overall funding needs.

虽然值得称赞，但在应对如此规模的全球性问题时，单凭他们的努力只是沧海一粟。

While commendable, their efforts alone are ___a ___drop ___in ___the ___ocean when addressing a global issue of this scale.

对于所需的大规模环境清理工作而言，政府的新拨款只是沧海一粟。

The government's new funding is ___a ___drop ___in ___the ___ocean for the vast environmental cleanup required.