This hand book is __for us to learn our lessons A.great value B.g_英语解答

This hand book is __for us to learn our lessons A.great value B.great valuableC.of great value
答案是选C,但我不知道为什么,谁能解释一下啊?谢谢

人气：202 ℃　时间：2020-04-20 11:36:30

解答

of great value=very valuable
of加上名词=形容词