The Hydrosphere is the watery part of the Earth's surface including oceans, rivers, lakes and water vapour.

(i) The Great Rift valley in Africa has many sites that have evidence for the prehistoric period.
(ii) The Great Rift valley is a valley - like formation that runs for about 6,400 km from the Northern part of Syria to Central Mozambique in East Africa.
(iii) This geographical feature is visible even from the space, and many prehistoric sites are found in Africa

(i) Most Earthquakes and Vqtcanic eruptions do not strike all the places but occur along the plate boundaries
(ii) One such area is the circum- Pacific Ring of Fire where the Pacific plate meets many surrounding plates.
(iii) It is the most seismically and volconically active zone in the world.

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.

1. In the course of evolution, humans became conscious and knowledgeable.
2. They turned curious and began to think and ask questions.
3. At first, they considered nature as God.
4. They worshipped sun, moon and various natural forces about which they developed their own understanding.

(a) The concept 'survival of the fittest' contributed to the scientific understanding of human origins.

a) Pacific Ring of fire: It is a major area and an arc in the_basin of the Pacific ocean where many earthquakes and volcanic eruptions occur.

(b) Earthquake-prone zones (any two): Turkey, Indonesia

(c) Locate any two active volcanoes of the world: Hawaii-, Mount Fuji

(d) Himalayas and Alps ranges

(i) In democracy Fundamenta! Rights are safeguarded to all the people.
(ii) All the People have equal rights.
(iii) People from all walks of life are treated equally.
(iv) People can elect their own leader.

In my locality i found the following environmental problems:
1. Air pollution: As there are a number of vehicles in my area the air pollution in very high Whenever I walk on the road, I could smell the carbon dust emitted from the vehicle.
2. Water pollution: Previously we could get clear water from our taps. Now the water is muddy and polluted.
3. Soil Pollution: Because of the incrase of air pollution we could find the soil polluted in our area.

(i) Rice was probably cultivated in India and China around 7000 BCE or even earlier.
(ii) Wheat and barley were cultivated at Mehrgarh in northwestern part of the Indian subcontinent (Pakistan) before 6000 BCE.
(iii) Animal domestication developed as part of symbiotic life.
(iv) Dogs may have been domesticated first. Friendly animals were gradually domesticated. Sheep and goat were domesticated around 10,000 BCE in Southwest Asia.
(v) Oxen were used in Sumerian civilisation for tilling the land. Mehrgarh in Pakistan has evidence of sheep, goat and cattle domestication in the Neolithic period.

(i) India has a Parliamentary form of democracy.
(ii) The Indian Parliament comprises the elected representatives of people.
(iii) It makes the laws for the country.
(iv) The participation of people in the decision making and the consent of citizens are the two important elements of Parliamentary form of government in India.
(v) India is the largest democratic country in the world.
(vi) Democracy in India works on five basic principles.
(vii) These are sovereign, socialist, secular, democratic and republic.
(viii) Every citizen of India who is not less than 18 years of age can exercise their right to vote in India.
(ix) There is no descrimination based on a person's caste, creed, religion, gender and education when it comes to providing the right to vote.

1. They are found at Chennai, North Arcot, Dharmapuri, Salem, Coimbatore, ariyalur, Trichi, Pudukottai, Madurai, Sivagangai, Tirunelveli and Kanyakumari.
2. The people of this period used small artefacts made of Chert and Quartz.
3. The tool types are scrapers, lunates and triangles.
4. These people hunted wild animals and gathered fruits, nuts and roots for their subsistence.