CBSE Class 11 English Unseen Passage F. Students should do unseen passages for class 11 English which will help them to get better marks in English class tests and exams. Unseen passages are really scoring and practicing them on regular basis will be very useful. Refer to the unseen passage below with answers.
But first - just what is an earthquake? And what causes it? In the early history the earth, when it was cooling down, the rocks deep in the earth's crust created huge 'islands’ which floated on the softer and hotter rocks below rather like wood floats on water. Slowly, these islands drifted apart to make the land- masses we know today as continents. But even now these 'islands' are not stable, and are still drifting very, very slowly.
It is these imperceptible movements which create stresses in the rock, many miles below the surface. Every so often, one of these stresses will break and on the surface the deep underground movement is felt as an earthquake.
There are three large regions in the world where earthquakes are most likely to happen. Scientists call them earthquake zones. The first runs along the east coast of the Asian continent up through Japan, across Alaska, then down the west coast of North America, crossing Mexico and ending somewhere in the Caribbean Sea. The second runs down the west coast of South America. The third runs across the south of Europe and North Africa, through Greece and Turkey and into the middle of Asia.
Earthquake, any sudden shaking of the ground caused by the passage of seismic waves through Earth’s rocks. Seismic waves are produced when some form of energy stored in Earth’s crust is suddenly released, usually when masses of rock straining against one another suddenly fracture and “slip.” Earthquakes occur most often along geologic faults, narrow zones where rock masses move in relation to one another. The major fault lines of the world are located at the fringes of the huge tectonic plates that make up Earth’s crust. (See the table of major earthquakes.)
About 50,000 earthquakes large enough to be noticed without the aid of instruments occur annually over the entire Earth. Of these, approximately 100 are of sufficient size to produce substantial damage if their centres are near areas of habitation. Very great earthquakes occur on average about once per year. Over the centuries they have been responsible for millions of deaths and an incalculable amount of damage to property.
1.1 On the basis of reading the above passage answer the following questions:-
1.) What do we know about these 'islands' even now?
2.) How is earthquake caused?
3.) Which is the first earthquake zone?
4.) Which is the second earthquake zone?
5.) Which is the third earthquake zone?
1.2 Find the meaning of the following words and phrases from the passage:-
(i) too great to be calculated (para 5)
(ii) undetectable (para 2)
(iii) unexpectedly (para 4)
(iv) manufacture (para 4)
Suggested answers for the above passage:
1.Even now, we know about these ‘island’ that they are still drifting very, very slowly.
2.Earthquake is caused when one of the stresses breaks and deep underground movement is felt.
3.The first earthquake zone runs along the east coast of the Asian continent up through Japan, across Alaska, then down the west coast of North America, crossing Mexico and ending somewhere in the Caribbean Sea.
4.The second zone runs down the west coast of South America.
5.The third earthquake zone runs across the south of Europe and North Africa, through Greece and Turkey and into the middle of Asia.