Because, it is the process by which they make or produce their food with the help of sunlight, water and carbon dioxide.
If photsynthesis is not there then there would be no production of food and ultimatley plants will die.
The correct answer is "ovulation" and "corpus luteum" respectively. In ovulation, the egg ruptures from the mature follicle (called the Graafian follicle). This process is preceded by the sudden rise in luteinizing hormone. The follicle now becomes the corpus luteum, actually does not secrete estrogen, it secretes progresterone which prepares the uterine lining for pregnancy.
Compare it to respiration in the human body or like how a car converts fuel to work or how a machine works because of electricity
i dont understand what you are saying but water gets evaporated from the oceans due to the suns warmth all the water vapors condense, once the clouds get too heavy and there are too many water vapors in the cloud for it to handle, it percipitates (rains)
