在过去的20亿年来，许多小行星和彗星撞击月球，留下撞痕，并在月球表面上遗留下大约10000亿吨水。

In the past 2bn years, asteroids and comets have ploughed into the moon, dumping an estimated ten thousand billion tonnes of water onto its surface.

youdao

在过去的20亿年来，许多小行星和彗星撞击月球，留下撞痕，并在月球表面上遗留下大约10000亿吨水。

In the past 2bn years, asteroids and comets have ploughed into the moon, dumping an estimated ten thousand billion tonnes of water onto its surface.

youdao