J. J. Thompson discovered the first subatomic particle, , by deflecting a "cathode ray" beam with an electric field. Robert Millikan later determined that
particle's charge in his "oil drop" experiments.
A) the proton
B) the nucleus
C) the neutron
D) the electron

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.