We need to know something about weatern culture and customs.(保持原意)We need to know something about weatern culture and customs.(保持原句意思)___ ___ for us to know something about western culture and customs.
问题描述：
We need to know something about weatern culture and customs.(保持原意)
We need to know something about weatern culture and customs.(保持原句意思)
___ ___ for us to know something about western culture and customs.
答
_It's__ _necessary__ for us to know something about western culture and customs.
necessary 也可以用 important, essential,等等