Answer: C) Sound waves Explanation: Light and Radio waves are both different frequency/wavelengths of electromagnetic radiation, which consists of two components electric and magnetic of perpendicular, transverse waves.    Sound, on the other hand, is a longitudinal wave which oscillates parallel to it's medium (back and forth instead of up and down).

Answer: A) Protects lungs Explanation: When you breathe in air through your nose, it contains lots of tiny things, like dust, dirt, germs, and pollen. The air enters our body through the nose. However, before it enters the lungs, it must be heated and purified. Many dust particles that enter along with the air are removed in the nose by mucus and thus it protects lungs.

The antagonist is the negative or opposing force in a story. It could be a human enemy, or it could be non-human, like an animal or something less tangible, like fear.   The antagonist plays an important role in story development.

Answer: B) Building a Digital World Consumers can Trust Explanation: World Consumer Rights Day is being observed today (15 March 2017) which is an awareness day and theme for this year is 'Building a Digital World Consumers can trust'.

Answer: A) Kazakhstan Explanation:

Answer: A) Argon Explanation: The most common gas people breathe from clean air is nitrogen. Air is a mixture of gases, and the air on Earth contains about 78 percent nitrogen and about 21 percent oxygen. Argon, carbon dioxide neon, helium, methane, krypton, hydrogen and xenon are in much smaller amounts.

Answer: D) Israel Explanation:

Answer: A) 2000 Explanation: Let 's' be the number of small packets and 'b' the number of large packets sold on that day.   Therefore, s + b = 5000 ... eqn (1)   Each small packet was sold for Rs.150.Therefore, 's' small packets would have fetched Rs.150s.   Each large packets was sold for Rs.250.Therefore, 'b' large packets would have fetched Rs.250b.   Total value of sale = 150s + 250b = Rs. 10.5 Lakhs (Given)   Or 150s + 250b = 10,50,000 ... eqn (2)   Multiplying equation (1) by 150, we get 150s + 150b = 7,50,000 ... eqn (3)   Subtracting eqn (3) from eqn (2), we get 100b = 3,00,000Or b = 3000   We know that s + b = 5000So, s = 5000 - b = 5000 - 3000 = 2000.   2000 small packets were sold.