[单选题]
The infrared spectrum of an organagv1d6q /gt9 aic compounf*:6ycu2 -aqxxqdb;kud3 /uamw( :mgd is shown.
What are the units of the variable X, shown on the $x$-axis of the infrared spectrum?
A. $cm^{-1}$
B. $Hz$
C. $nm$
D. $ppm$
参考答案: A
本题详细解析: Explanation:
Simple recognition of the units used in an IR spectrum. Since the information is given in the syllabus and covered frequently, this question is categorised as easy.
