please help me in this I will mark as the brain list
Answers
Q4.
a) Dissolved oxygen (DO) is one of the most important indicators of water quality. It is essential for the survival of fish and other aquatic organisms. Oxygen dissolves in surface water due to the aerating action of winds. Oxygen is also introduced into the water as a byproduct of aquatic plant photosynthesis.
b) your hand is translucent.
c) At home, we usually store things in such a manner that similar objects are placed together. Such an arrangement helps us to locate them easily. Similarly, a grocer usually keeps all type of biscuits at one corner of his shop, all soaps at another while grains and pulses are stored at some other place.
d) Most electrical wire is covered in a rubber or plastic coating called insulation. ... The purpose of insulation covering the metal part of an electrical wire is to prevent accidental contact with other conductors of electricity, which might result in an unintentional electric current through those other conductors.
e)Anything which has mass and occupies space is called matter. The matter in which an object is made is called material. All the objects are made up of one or more materials.
Objects Constituent material
Concrete Cement, gravel, sand, water
Ball-pen Plastic, metal, ink
f) water is called the "universal solvent" because it dissolves more substances than any other liquid. This is important to every living thing on earth. ... This allows the water molecule to become attracted to many other different types of molecules.
Hope it helps...