Page 133 - Grammar Class 07

2. Define the following.

a. Space ____________________________________________________________
b. Planet ____________________________________________________________

3. Answer the following questions.
a. What is the full form of NASA?
b. Where is NASA head quartered?

c. What is role of astronauts in NASA?
d. Which programes helped NASA?
e. When was NASA started?
f. What do NASA scientists do?

B. Read the passage and answer the questions that follow.

Clouds are made of tiny droplets of water or ice flakes that settle on dust particles in
the atmosphere. Clouds are either composed of ice or water droplets depending on
the height of the clouds and the temperature of the atmosphere. Because of their
small size, droplets can remain in liquid form in temperatures as low as –30°C.

Clouds are formed when the invisible water vapour in the air condenses into visible
water droplets or ice flakes. There is water around us all the time in the form of
water vapour. There are also tiny particles floating around in the air such as salt and
dust, also called aerosols. Water vapour and aerosols are constantly bumping into
each other. When the air is cooled, some of the water vapour sticks to the aerosols as

they collide. This is known as condensation. Eventually, bigger water droplets are
formed around aerosol particles and these water droplets start sticking together with
other droplets transforming into clouds. Clouds are formed when the amount of
water in the air is saturated and cannot hold any more water vapour. This can
happen when the amount of water in the air has increased and when the air is
cooled to its freezing point. The surface heating and the shape and features of the
area are some of the causes of formation of clouds. The range of ways in which

clouds can be formed and the variable nature of the atmosphere result in the
formation of different shapes, sizes and colours of the clouds.

1. Fill in the blanks.
a. Clouds are formed when the _____________ water vapour in the air condenses
into _____________ water droplets or ice flakes.

b. Clouds are of different _____________, _____________ and _____________.
c. Water vapour and aerosols are constantly _____________ into each other.

d. Droplets can remain in liquid form in temperature as low as ______ °C.
e. Clouds are made of tiny droplets of _____________.

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Grammar-7