Directions (For the following 5 items): The passage given below is followed by questions based on its content. After reading the passage, choose the best answer to each question. Answer all the five questions following the passage on the basis of what is stated or implied in the passage.
Passage
Ocean water plays an indispensable role in supporting life. The great ocean basins hold about 300 million cubic miles of water. From this vast amount, about 80,000 cubic miles of water are sucked into the atmosphere each year by evaporation and returned by precipitation and drainage to the ocean. More than 24,000 cubic miles of rain descend annually upon the continents. This vast amount is required to replenish the lakes and streams, springs and water tables on which all flora and fauna are dependent. Thus, the hydrosphere permits organic existence.
The hydrosphere has strange characteristics because water has properties unlike those of any other liquid. One anomaly is that water upon freezing expands by about 9 percent, whereas most other liquids contract on cooling. For this reason, ice floats on water bodies instead of sinking to the bottom. If the ice sank, the hydrosphere would soon be frozen solidly, except for a thin layer of surface melt water during the summer season. Thus, all aquatic life would be destroyed and the interchange of warm and cold currents, which moderates climates, would be notably absent.
Another outstanding characteristic of water is that water has a heat capacity which is highest of all liquids and solids except ammonia. This characteristic enables the oceans to absorb and store vast quantities of heat, thereby often preventing climatic extremes. In addition, water dissolves more substances than any other liquid. It is this characteristic which helps make oceans a great storehouse for minerals which have been washed down from the continents. In several areas of the world these minerals are being commercially exploited. Solar evaporation of salt is widely practised, potash is extracted from the Dead Sea, and magnesium is produced from sea water along the American Gulf Coast.
11. Which one of the following is correct?
According to the passage, the hydrosphere is not
- Aresponsible for all forms of life
- Bable to modify weather
- Ca source of natural resources
- Din danger of freezing over
Explanation
The passage says the hydrosphere is indispensable to life ("plays an indispensable role in supporting life", "permits organic existence"), that it moderates climate (warm/cold currents, oceans storing vast heat "preventing climatic extremes"), and that it is a "great storehouse for minerals" being commercially exploited (salt, Dead Sea potash, Gulf Coast magnesium). The "frozen solid" scenario is only a counterfactual — "if the ice sank" — which does not happen precisely because ice floats. So the one thing the passage does NOT assert is that the hydrosphere is in danger of freezing over.