Questions

A greenhouse gas is a gas in an atmosphere that absorbs and emits radiant energy within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. 

Carbon dioxide is a main greenhouse gas, found in car exhaust pipes.
Methane and nitrous oxide is another type of greenhouse gas.

Oxygen is the only clean gas out there because we need it to survive. Therefore, the only gas that is not a greenhouse gas is Oxygen.

Sound is a mechanical vibration and needs a medium for propagation. The higher the density of the medium, the faster the sound travels. So, sound cannot travel through vacuum.

As the sound travels faster in solids than liquids and gases, sound travels faster in the glass than Air and water.

A place where monks live as a secluded community is Monastery.

The World Health Organization is a specialized agency of the United Nations that is concerned with international public health. It was established on 7 April 1948, Headquartered in Geneva, Switzerland.

Dr Soumya Swaminathan has been appointed the deputy director general for programmes (DDP) of World Health Organisation (WHO). She also holds a key position as secretary in the department of health research, ministry of health and family welfare.