We must know such symbols____are used to represent the chemi

We must know such symbols____are used to represent the chemical elements.
A that B whtat C which D as
正确答案是Das,为什么不是Athat呢?
答：D
分析：这题考查定语从句的特殊句型. 当先行词被such, 或so+ adj.+a 所修饰时,用关系代词as,不用that
译：我们必须知道那些被用来代表化学元素的符号.
关于这一语法点,语法书上有谈到,但一般不说理由.我是猜的,供参考：
因为so/such... that... (结果状语从句）太深入人心了.为了避免让人误入歧途,故用关系代词as,而避开了关系代词that.
如：Such people as you mentioned are rare nowadays.
但是有些出题的老师却为了让人误入歧途故意将本用状语从句的改成了定语从句：
He is such a good teacher ______ we all like.
A. that B. as C. who D. whom
当你选A之后,他告诉你：错了,请注意,like后没宾语,这是定语从句!
可有这样的限制性定语从句吗?