Questions

Biogeochemical cycles are crucial to ecosystem function because ::

1. Chemical elements are available in only limited amounts and must be recycled.

2. Nutrients and other life-sustaining molecules are in limited supply and must be continually recycled.

A Jig saw puzzle pieces are in different colors which have different shapes. 

You can put it anywhere you like but there is only one right place for it to be fit in it.

Venus is known as earth's twin because of its closeness to the earth with respect to size, mass(weight) and density.

Tubes that bifurcate from the windpipe are called Bronchi.

The amount of water vapor in the air is called Humidity. The amount of water vapor that air acn hold depends on the temperature of the air. The amount of water vapor in the air as compared with the amount of water that the air could hold is called Relative humidity.

The simplest organic compounds contain only the elements carbon and hydrogen, and are called hydrocarbons.

Here all the given options are hydrocarbons.