Answer: A) Autotrophs Explanation: Plants make their own food through the process of photosynthesis. Plants are self-sufficient. Green plants have the ability to prepare their own food and this is the reason why they are called autotrophs.                                          They make their own food through the process of photosynthesis using light energy to make sugars from carbon dioxide (C02) and water (H20). The chlorophyll which is present in the leaves is the main reason for the production of food in the plants and it is the reason for the greenery of the leaves too.

Answer: B) 0 Explanation: No work done as there is no external external pressure in free expansion.    Hence, Work done in a free expansion process is Zero.

Answer: D) All the above Explanation: Global warming is the increase in the earth’s average temperature due to release of several greenhouse gases to the atmosphere by humans. Global warming is affecting many parts of the world.   Natural Causes include : 1. Solar Activity 2. Melting Permafrost 3. Forest Fires    Human made causes include : 1. Deforestation 2. Overpopulation 3. Landfills 4. Mining 5. Fertilizer Use

Answer: C) Cable television Explanation: Cable television or cable TV became widespread during the 1980's.

Answer: B) Lungs Explanation: Emphysema is a condition that involves damage to the walls of the air sacs (alveoli) of the lung i.e, primarily causes shortness of breath due to over-inflation of the alveoli.   First, emphysema causes holes to gradually form inside the lungs' air sacs, thereby weakening their internal structure and inhibiting the exchange of oxygen and carbon dioxide.

Answer: D) ATP, Water Explanation: Cellular respiration is the three-step process by which cells make ATP using glucose and oxygen. Oxygen and glucose are both reactants in the process of cellular respiration. The main product of cellular respiration is ATP, waste products include carbon dioxide and water.

Answer: A) if all the resources of an economy are in use, more of one good can be produced only if less of another good is produced. Explanation: A graph that describes the maximum amount of one good that can be produced for every possible level of production of the other good is nothing but a production possibilities curve.

A Bath towel or a tea bag are suitable answers.