Which of the following organisms first introduced oxygen into earth's atmosphere?
a. cyanobacteria
b. methanogens
c. early protozoans
d. plants
e. green algae

Cyanobacteria were the first organisms to introduce oxygen into Earth's atmosphere. They were also known as blue-green algae, and is estimated that they first appeared around 3 billion years ago.

Tamarind can be grown on homesteads, plantations, and wasteland or as a forest tree. methods of propagating tamarind there are two methods of propagating tamarind trees: seed propagation and vegetative propagation. seed propagation: it involves the collection, preparation and direct planting of the seed.answer from google full credit to google.