Which of the following are true?

a. primary succession begins in an area that does not have soil.

b. secondary succession occurs in an area that already had life and soil.

c. primary succession begins in an area that did not have life before.

d. all of these are true.

What do science, technology, and disease have to do with each other?

You have 2 plants of the same type and same size, same amount of leaves. one of them is put inside the house and the other one is put in the balcony. you water them saturday, one plant with 200 ml and the other with 400 ml of water. which one of your plants need less water? explain.

How do accessory pigments chlorophyll?