Every year one hundred trees remove approximately from the atmosphere.
a. five tons of carbon dioxide
b. four hundred pounds of ozone
c. three hundred pounds of particulates
d. all of the above

The correct answer would be d. all of the above.

Trees are of utmost importance for well being of our atmosphere or environment.

They help in reducing air pollution by limiting the carbon content and increasing the oxygen level of the atmosphere.

In addition, they absorb other harmful gases such as sulfur dioxide, nitrogen dioxide, and carbon monoxide.

Trees also release volatile organic compounds which form ozone with the help of sunlight.  

They also act as natural air filters and help in filtering air dust particles other air pollutants.

It is estimated that one hundred trees remove approximately  five tons of carbon dioxide, four hundred pounds of ozone, and three hundred pounds of particulates from the atmosphere in a year.

advantage of using stem cells in medical research:

1.       it provides medical benefits in the fields of therapeutic cloning and regenerative medicine.

2. it provides great potential for discovering treatments and cures to a variety of diseases including parkinson disease, spinal cord injuries, diabetes, alzheimer’s disease and many more.

3. limbs and organ could be grown in lab from stem cells and then used in transplant or treat illness.