Answer: C) H2O Explanation: The common greenhouse gas containing only hydrogen and oxygen is H2O, this is water vapor. The common greenhouse gases are water vapor, carbon dioxide, methane, nitrous oxide, and ozone. The composition (chemical formula) of those gases are: Water vapor: H2OCarbon dioxide: CO2Methane: CH4Nitrous oxide: NOOzone: O3. As you see the only one of those that contains only hydrogen and oxygen is H2O, water vapor.

Answer: A) Gorkha National Liberation Front Explanation: GNLF stands for Gorkha National Liberation Front.   Gorkha National Liberation Front (GNLF) is a political party in the Darjeeling District of West Bengal, India. It was formed in 1980 by Subhash Ghisingh with the objective of demanding a Gorkhaland state within India.

Answer: A) Erosion Explanation: Caverns are openings in the ground. Some famous caverns in the United States are Mammoth Cave, Carlsbad Caverns, Wind Cave, and Luray Caverns.   When rainwater trickles down through the soil, it carries carbon dioxide from the air with it. This turns acidic as it moves through the soil, joining with carbon from decaying plants. This acidic rainwater then eats away at, or erodes, the rock under the ground, forming a cave or cavern. For this process to occur, the rock must be the right type; limestone, dolomite, and gypsum are common.

Answer: D) Panacea Explanation: Panacea, also known as panchrest, is a medicine supposed remedy that is claimed to cure all diseases and prolong life indefinitely. It is named after the Greek goddess of universal remedy Panakeia.

Answer: C) AVARD Explanation:

Answer: D) A wildlife management agency Explanation: A wildlife management agency sets hunting regulations in most states.     These agencies will have regular meetings where the public can voice their concerns and make suggestions. Hunters wishing to propose changes to the regulations should participate in these meetings or join a hunting organization that interacts with the agency.

Answer: D) Apiculture Explanation: Breeding and management of bees is called Apiculture.   A beekeeper or apiarist keeps bees in order to collect their honey and other products that the hive produces (including beeswax, propolis, flower pollen, bee pollen, and royal jelly), to pollinate crops, or to produce bees for sale to other beekeepers. A location where bees are kept is called an 'apiary' or 'bee yard.'