PASS YOUR MOUSE OVER THE QUESTION MARKS (???) FOR THE ANSWER TO EACH QUESTION! ANSWER WINDOW WILL OPEN. JUST CLICK OK TO MAKE THE ANSWER GO AWAY AND GO ON TO THE NEXT QUESTION!

1. Textile workers more frequently suffer from ?

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2. Coal miners more frequently suffer from?

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3. The type of living beings more sensitive to nuclear radiations are?

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4. The most acute pollution problem faced by nuclear power industry is?

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5. Excessive inhaling of manganese causes?

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6. Hay fever is due to the presence of ..... in the air.?

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7. The metal which causes systemic poisoning in man is?

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8. Dust containing silica causes?

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9. Intensive use of nitrate fertilizers causes?

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10.The most economic and pollution free form of transport is ?

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11.The main source of harmful radiations in our houses can be due to?

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12.The regions of the surface and atmosphere of the Earth (or other planet) where living organisms exist is known as?

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13.The region which was once called the fertile crescent of the world was?

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14.The most recently discovered ecosystem is?

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15.  15.The most biologically productive ecosystem is?

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16.The ecosystem where the species diversity is lowest is?

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17. Ecologists divide lakes into ........ zones?

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18.Death valley is located in the ...... desert?

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19.Presently glaciers cover ..... percentage of land surface of the earth.

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20.Watershed is the boundary of a ridge of high ground between?

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