a) Uranus
b) Green
c) Due to the presence of methane

a. Mercury
b. Jupiter
c. Uranus
d. Mars

(i) The earth is the most suitable planet to support life.
(ii) It has thrge major components that we call as the realms of the Earth lithosphere, hydrosphere and atmosphere.
Lithosphere:
(i) The lithosphere is the land on which we live.
(ii) It is the solid outer layer of the earth consisting of rocks and soils.
Hydrosphere:
(i) The hydrosphere consists of water bodies such as oceans, seas, rivers, lakes, ice caps.on mountains and water vapour in the atmosphere.
Atmosphere:
(i) Atmosphere is the envelope of air that surrounds the earth.
(ii) Different types of gases make up the atmosphere.
(iii) The major gases are Nitrogen 78% and Oxygen 21%.
(iv) The other gases like Carbon dioxide, Hydrogen, Helium, Argon and Ozone are present in meager amounts.
Biosphere:
(i) The narrow belt of interaction among the lithosphere, the hydrosphere and the atmosphere, where life exists is known as biosphere.
(ii) Bio means life in Greek.
(iii) It consists of distinct zones.
(iv) Each zone has its own climate, plant and animal life.
(iv) These zones are known as ecosystems.

Rotation:
(i) It is the spinning movement of the earth on its axis.
(ii) The rotation of the earth causes day and night.
(iii) As the earth is spherical in shape, only one half of it is illuminated by the sun at a time.
(iv) The other half remains dark.
(v) The illuminated portion of the earth experiences day, whereas the darkened part of the earth experiences night.
Revolution:
(i) It is the movement of the earth around the sun on its elliptical path.
(ii) The inclination of the earth on its axis and its revolution around the sun cause different seasons.