When oil drilling first began, it was common practice to burn off the lower density hydrocarbon gases, like methane, that often accumulate along the top of an oil trap. This process is known as _______________ and today, methane is collected as a valuable resource.
Fill in the blank(s) with the appropriate word(s).
Question 2The injection fluid used in hydrofracking consists of ____.
a. aerobic bacteria and water c. chemicals, sand, and water
b. fertilizer and water d. water only
