(i) A valley is made deeper by a stream of water (or) a river as it flows from the high land.
(ii) The valleys are either 'U' shaped or 'V' shaped.
(iii) The glacier debris get deposited in the low lying areas. So glaciers do not form deep narrow valleys.

Cyclones can be classified into
(i) Tropical cyclones
(ii) Temperate cyclones
(iii) Extra Tropical cyclones

(i) A visible mass of condensed water vapour floating in the air above the ground level is called is cloud.
(ii) Cool moisture laden air gets collected around particles like dust, salt content from the sea, smoke, etc, and forms clouds.
(iii) Sometimes mixing warmer and cooler air also produces clouds.

(i) Isotherms are imaginary lines drawn on maps, connecting points that have equal temperatures.
(ii) Temperature varies from place to place, season to season and continent to continent.

1. The Ziggurats were at the city centre on a platform and appeared like steep pyramids, with staircases leading to the top.
2. Around this temple were complexes of ceremonial courtyards, shrines, burial chambers for the priests and priestesses, ceremonial banquet halls, along with workshops, granaries storehouses and administrative buildings.

(i) The word 'Tsunami' is a Japanese term meaning harbour waves.
(ii) It is generated sea waves caused by Earthquakes, submarine explotions and landslides.
(iii) These waves travel more than 500 km per hour. These waves are called Tsunami.

(i) The Earth is a unique planet of the Solar family.
(ii) The Earth is composed of four spheres.
(iii) They are lithosphere, the atmosphere, the hydrosphere and the biosphere.
(iv) The four spheres of the Earth interact with one another.
(v) The abiotic spheres are the lithosphere, atmosphere and hydrosphere.
(v) The biotic sphere is the biosphere.

1. In Megalithic period people buried the dead bodies with grave goods in the cists.
2. Urns or pottery jars were used for burning the dead and also they used sarcophagi made of terracotta.
3. Dolmens, table like stone structures were erected as funerary monuments. Menhirs pillar are like stones erected as part of the burials or memorials.
4. Port holes are holes found in the cists and dolmens on one side.

(a) Zoroaster of Persia is the founder of Zoroastrianism.
(b) Ahura Mazda (the Lord of lights).
(c) Zoroaster taught that the great object of religion state or society is the cultivation of morality.
(d) Fire was worshipped as a symbol of the deity and considered the highest form of worship.

(a) As cattle were considered an important source of wealth, raiding cattle owned by adjoining. tribes and clans was common practice in a pastoral society.
(b) Tribal chieftains plundered the cattle wealth of enemies whose warriors fought to protect their cattle.
(c) (i) Many warriors died in such battles and were remembered as martyrs.
(ii) Memorial stones were erected in their honour.
(d) Which Tamil text describes the procedures for erecting hero stones?

(a) Hominids refers to all the species of the modern and extinct great apes, which also includes humans.
(b) Homo habilis (handy human) was the earliest known human ancestors to make tools in Africa about 2.6 million years ago.
(c) Modern-humans are known as Homo Sapiens.
(d) Homo erectus - extinct
Humans are the only living species.

1. The pyramids are massive monuments built by Egyptians as tombs of mourning to the Pharaohs. The Great Pyramids near Cairo are known as the Gizza Pyramids.
2. (a) The Egyptians had the tradition of preserving the dead bodies using Natron salt, a combination of sodium carbonate and sodium bicarbonate.
(b) The preservation process is called mummification.
(c) After 40 days when the salt absorbed all the moisture, the body was filled with sawdust and wrapped in strips of linen clothes and covered with fabric. The body was stored in a stone coffin called sarcophagus.
3. (a) The Egyptians believed in life after death.
(b) Egyptian practiced polytheism. They worshipped many Gods.
4. The Great sphinx of Giza is a massive limestone image of a lion with a human head. It is dated to the time of Pharaoh Khafre. It is one of the largest sculptures of the world and measures seventy three metres in length and twenty metres in height.

(i) I will not have the right equality under dictatorship. Because the dictator is a political leader who rules the state with absolute power.
(ii) In such a country the public opinions are suppressed. People will be given less rights or no rights.

(i) Limestone is made up of Calcium Carbonate.
(ii) It dissolves in water easily.
(iii) So during rainfall the water at the joints and fractures of the limestone seeps easily underground.
(iv) So the underground water is more common than the surface run off.