Directions: In the following questions, some parts of the sentences have errors and some have none. Find out which part of a sentence has an error. The number of that part is your answer. If a sentence is free from error, then your answer is (4) i.e. No error

Q:

Water contamination has become more serious (1)/ since chemists have begun to use (2)/ new substances. (3)/ No error. (4)

• 1
  1
• 2
  2
• 3
  3
• 4
  4