A. Kidneys removes extra salts and water from the blood
B. The urine is stored in Urinary bladder
C. Through urethra urine is excreted out of the body.
D. Ureter transfer urine from the kidneys to the urinary bladder.

We get electricity from thermal power, hydel power, tidal power wind power, solar power etc as sources of electricity
Thermal Power stations:
In thermal power stations, the thermal energy generated by burning coal, diesel or gas is used to produce steam. The steam is used to rotate the turbine. While the turbine rotates, the coil of wire kept between the electromagnet rotates. Due to electro magnetic induction electricity is produced. Here heat energy is converted into electrical energy.
Hydel power stations:
In hydel power stations, the turbine is made to rotate by the flow of water from dams to produce electricity. Here kinetic energy is converted into electrical energy. Hydel stations have long economic lives and low operating cost.
Atomic power stations:
In atomic power stations, nuclear energy is used to boil water. Here the steam is used to rotate the turbine. As a result, electricity is produced. Atomic power stations are also called as nuclear power stations. Here nuclear energy is converted into mechanical energy and then electrical energy.
Wind Mills:
In wind mills, wind energy is used to rotate the turbine to produce electricity. Here kinetic energy is converted into electrical energy.

(i) Computers are used in various fields.
(ii) In textile shop it is used for billing.
(iii) Computers are used to control large and small machines.
(iv) Computers are most important educational tools for teachers and learners.
(v) In Railways it is useful to book tickets and for other purposes.
(vi) It is also used in banks, ATM's, Post offices and in many places.
(vii) We can save many data and convert it into information.

When there is a change of position of an object with respect to time then it is called motion.
Types of motion:
a) Based on path:
i) Linear motion - a person walking on a straight path
ii) Curvilinear motion - throwing ball
iii) Circular motion - swirling stone tied to the rope
iv) Rotatory motion - a rotating top
v) Oscillatory motion - pendulum of clock
vi) Zig zag (or) Irregular motion - the motion of a bee
b) Based on duration:
i) period motion - movement of hour hand of a clock
ii) Non-periodic  - motion flapping of a flag in wind
c) Based on speed:
9) Uniform motion -  motion of a train at a constant speed
ii) Non-uniform motion - a vehicle moves in different speed

(i) The rib cage is made up of 12 pairs of curved, flat rib bones.
(ii) It protects the delicate vital organs such as heart and lungs.

They are exposed to harsh weather conditions, dust, pollution, heat and cold. So, they can have an adverse effect on their health. Hence, they weak a mask on duty.

No the cell used in the clock cannot give us an electric shock because the voltage is very low in the cell.

Adaptive features of polar Bear : Thick skin for protection, White fur.
Adaptive features of Penguin : Paddle to swim, walk with two legs.

a) Neem tree
b) Mango tree
c) Croutons
d) Coconut tree

Arteries, Veins and capillaries are the blood vessels.

If we remove the fish from the aquarium and keep it in a dark place with green plants,
(i) they can't have sunlight and
(ii) have no CO₂ from the water produced by fish as they breathe.
(iii) Simply say, there is no possibility for photosynthesis to make their food.

When solute is dissolved in a solvent it forms a solution.
Solute + Solvent ⟶ Solution

yes, I can produce electricity from lemon. Because lemon juice (Acetic acid) acts like a electrolyte.

The expansion of a substance on heating is called, the thermal expansion of that substance.

Lemon juice is a mixture because it is a miture of lemon extract, water and sugar.  This is a mixture though the amount of sugar and water added is different we know that, in a mixture the components are mixed in any proportion.

The area where a particular organism actually lives is called its habitat.

We should not wash the fruits and vegetables after cutting because they lose some of their nutrients and thus their nutritional value gets reduced.

c. Flash card

A - Exercise;
B - Yoga;

Thick walls are present in ventricles to pump the blood from the heart to various part of body.

a) melting of wax and
d) Solidification of the molten wax can be reversed.
Burning of candle is a physical / reversible change. That is,
\(\text { Solid wax } \underset{\text { Cooling }}{\stackrel{\text { Heating }}{\rightleftarrows}} \text { molten wax }\)