Ozone production via automobile emissions ________.
a. is usually associated with photochemical smog
b. can help restore the ozone being depleted in the outer atmosphere
c. is eliminated by appropriate use of catalytic converters
d. will provide overall worldwide reduction in skin cancer
Question 2
The vector sum of three co-planar forces
a. must be zero.
b. must be perpendicular to one of the three. c. must be parallel to one of the three. d. must be perpendicular to the plane. e. may have any direction in the plane.