General Science questions

1. The planet mercury is never away from the sun by more than:
a). 18 degrees
b). 28 degrees
c). 38 degrees
d). none of  these

2. At which location on the earth will the same object weigh the least:
a). South pole
b). North pole
c). Equator
d). none of these

3. Black holes are celestial bodies which have a strong:
a). Electric force
b). Magnetic force
c). Gravitational force
d). Cosmic force