The laws of physics demand that a neutron star has a maximum mass of ____ solar mass(es).
a. 1
b. 1.4
c. 3
d. 8
e. 20
Question 2
Kepler's first law of planetary motion states The orbits of the planets are _____ with the Sun at one focus..
a. spheres
b. ellipses
c. circular
d. rigid
e. random