Economic foods may take the form either of material things or service怎么翻译 为什么会加of

题目

Economic foods may take the form either of material things or service怎么翻译 为什么会加of

答案

take the form of 是个固定短语 ,意为：“表现为…的形式”
Investigations normally take the form of a preliminary examination.
研究工作通常包括初步验证.