that is needed for camping 是定语从句,that 是从句的主语,指代不定代词 everything,而 is 是从句的谓语动词。主语和谓语动词都是句子的必要成分,所以 is 不能去掉。
句中that引导的是定语从句作定语修饰everything。is needed是定从中的谓语,不可去掉助动词is。但可以去掉that is变成过去分词短语作定语即The shop furnishes everything needed for camping.
The shop furnishes everything that is needed for camping.是复合句
The shop furnishes everything needed for camping.是简单句。
二者意思一样。
可以去掉,但是要把that也去掉,这样就变成了分词短语做后置定语
is needed表被动作谓语
不能省略
concern 是不可数的抽象名词,零冠词。