Explanation

The lithosphere is the rocky outer part of the Earth.

It is made up of the brittle crust and the top part of the upper mantle.

The lithosphere is the coolest and most rigid part of the Earth.

Explanation

Virus is an ineffective agent that typically consists of a nucleic acid molecule in a protein coat,

is too small to be seen by light microscopy,

and is able to multiply only within the living cells of a host.

Explanation

A hygrometer is an instrument used to measure relative humidity.

Humidity is the measure of the amount of moisture in the air.

A psychrometer is an example of a hygrometer.

Explanation

A free-falling object has an acceleration of 9.8 m/s/s, downward 

Explanation

A pandemic is an epidemic of an infectious disease that has spread across a large region,

for instance multiple continents ,

affecting a substantial number of individuals.

Explanation

Hypothermia is caused by exposure to cold temperatures for a long time.

It can also occur after prolonged immersion in cold water. 

Causes 

Cold temperatures: Exposure to temperatures below 10°C for a long time

Cold water: Prolonged immersion in water below 20°C

Wet clothing: Wearing wet clothing in cold or windy weather

Heavy exertion: Exerting yourself while in cold weather

Dehydration: Not drinking enough fluids in cold weather

Undereating: Not eating enough in cold weather