English
1. Do
exercise A on page number 121 of your student book and submit on 13-03-17.
Science
Write
the following content given below in your science note book. Submit the same on
Monday, 13/3/17. Study the underlined words for a dictation on Tuesday,
14/3/17.
•
Air pressure is the weight of the
atmosphere pressing down on the earth. It is measured by a barometer in
units called millibars.
•
Air pollution occurs when
gases, dust particles, fumes (or smoke) or odor are introduced into the atmosphere
in a way that makes it harmful to humans, animals and plants.
•
Things that pollute the air are
called pollutants.
•
Causes of air
pollution
smoke from vehicles, factories, etc
refrigerators,
Ac s etc
·
Effects of air pollution
Acid rain
diseases in humans such asthma,
lung diseases etc
·
Ways to reduce air pollution
Walk to nearby places instead of going by car.
Turn off the car while waiting in the traffic signal.
Use eco- friendly bags.
Use renewable sources of
energy instead of non renewable sources.
S.St
Continue the given notes in your S.St. notebook and
submit on Monday 13/3/2017.
Unit-8
Air and Water
Q. What is the need and importance of air
and water?
A. Air
* Air has
always been important for breathing, combustion, photosynthesis, inflating
tyres, dispersal of seeds etc.
* Wireless
communication is possible because of air.
* Compressed air is used in machines used for
mining and digging.
Water
*
Water makes 71 per cent of the Earth's surface.
* We use
water for drinking, washing, cleaning, cooking, watering plants, transportation
etc.
Q. Write a short note on tides.
A. Tides are the
rise and fall of sea levels caused by the gravitational forces exerted by the
Moon and the Sun. The gravitational attraction of the Moon causes the oceans to
bulge out in the direction of the Moon. The rise in level of water is called
high tide. The fall in level is called low tide.
Tides are
helpful in fishing, trading, recreational boating and surfing and navigation.
Tidal force can be used to generate power.
NOTE: To be continued......
