Which of the following is NOT listed as a light oil

A．By expansion of the hydrocarbons.
B．By pressure and pumping.
C．By vacuum created in the drilling pipe.
D．By expansion and contraction of the earth's surface.

A．Shifiwork had a direct effect on the attitudes and behavior of family members.
B．Shifiworkers could live a normal life.
C．Shifiwork couples had unconventional ideas about marriage.
D．Female shifiworkers were satisfied with the time spent together with their families.