16. What is the farthest planet from the sun?
a) Neptune
b) Uranus
c) Saturn
d) Pluto
17. What is the closest planet to Earth?
a) Mars
b) Venus
c) Mercury
d) Saturn
18. What is the only planet in our solar system with a day longer than its year?
a) Venus
b) Mars
c) Uranus
d) Neptune
19. What is the only planet in our solar system that has liquid oceans on its surface?
a) Mars
b) Venus
c) Earth
d) Jupiter
20. What is the only planet in our solar system known to have a strong magnetic field and a liquid metallic core?
a) Mars
b) Venus
c) Earth
d) Uranus