Question

Chemists find _____ to detect and measure the amount of chlorine in any given water supply.

1. A.
   are easy
2. B.
   easily
3. C.
   it easy
4. D.
   how easily

Answer 1

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。