Ancient cultures took earth for a disk, but very soon the observation of stars and planets revealed that earth resembles a sphere. After the late 1700s measurements showed that earth is slightly flattened at the poles. What is the shape of the earth?

1. Sphere
2. Oblate
3. Oval
4. Oblate Spheroid

Given below are pairs of statements. Select the statements which prove the spherical shape of the earth.

(a) If there were no buildings in the way, we would be able to see another city that is hundreds of miles away.
(b) The boat would stay in view no matter how far out to sea it went.
(c) A ship slowly starts to disappear from view as it gets farther away.
(d) If we were to place two identical sticks in the ground in two different places, the length of their shadows differs.
(e) During a lunar eclipse, the sun projects Earth's shadow onto the moon and the shadow is round.

1. (a), (b), (c)
2. (b), (c), (e)
3. (c), (d), (e)
4. (a), (d), (e)

Earth happens to orbit the sun within the so-called "Goldilocks zone," where temperatures are just right to maintain liquid water on our planet's surface. Water covers roughly 71% of Earth's surface, with most of that water located in our planet's …………… .

1. Ice-caps
2. Glaciers
3. Oceans
4. Rivers

Assertion (A): Water on earth drastically tones down day and night temperature variation.

Reason (R): Water can absorb enormous amount of heat without causing much change in its temperature.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R does not explain A.
3. A is true but R is false.
4. A is false but R is true.