A-A+
We must know such symbols ______ are used to r
问题详情
We must know such symbols ______ are used to represent the chemical elements.
A．that
B．what
C．which
D．as
参考答案
正确答案：D
解析：在"such+n.+as"或"such as+…”或"the same+…+as"或"as+adj.+a/an+n.+ as"结构中，as作关系代词，引导定语从句，as在定语从句中可以作主语、宾语或表语，如：Ultrasonic sound is such as is inaudible to human ear．超声波是一种人耳听不到的声音。
