Tunnel Engineering

Pick up the correct statement from the following during tunnel excavation_____.

  • A. Oxygen should not be less than 19.5%
  • B. Carbondioxide should not be more than 0.5%
  • C. Hydrogen sulphide should not be more than 0.001%
  • D. All of the above
Answer: Option D.
Explanation: 

No answer description available for this question.

Leave a Reply

Your email address will not be published.

Back to top button
error: Alert: Content is protected !!