Chemists find _____ to detect and measure the amount of chlorine in any given water supply.
A.are easy
B.easily
C.it easy
D.how easily
网友回答
C解析后面的the amount of chlorine in any given water supply.虽然并不重要，但其过去分词given的用法和supply作为名词的使用以及名词water作为定语的使用特点，都值得注意。