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प्रश्न
Why do you think oxygen dissolved in water is important for the survival of aquatic animals and plants?
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उत्तर
The oxygen which is dissolved in water is used by animals for breathing and used by plants for breathing and photosynthesis.
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संबंधित प्रश्न
Very Short Answer Type Question:
Select a lustrous material out of the following substances.
Very Short Answer Type Question:
Which material is generally used for making pens? Wood, aluminum, plastic, cotton
When can you say a material is waterproof material?
Select those objects from the following which shine:
Glass bowl, plastic toy, steel spoon, cotton shirt
Vinegar dissolves in water.
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Complete the crossword given in the figure with the help of the clues.

Across
1. Which is generally hard, ductile, malleable and sonorous.
2. A metal is called so it can be drawn into wires.
3. Metal bells are used because of this property.
Down
4. A metal generally used for making jewellery.
5. A metal which is liquid at room temperature.
6. A metal which reacts with acid as well as base to form hydrogen gas.
7. Substances used to enhance the growth of plants.
8. Property by virtue of which metals can be beaten into thin sheets.
Pick one material from the following which is completely soluble in water.
Which of the following materials is not lustrous?
Sugar, salt, mustard oil, sand, sawdust, honey, chalk powder, petals of flower, soil, copper sulphate crystals, glucose, wheat flour are some substances given to Paheli. She wants to know whether these substances are soluble in water or not. Help her in identifying soluble and insoluble substances in water.
