7. What causes high and low tides? O A. The series of regular lunar eclipses
O B. The frictional coefficient of water
O C. The gravitational pull of the sun and the moon
O D. The rotation of the earth on its axis

the correct answer is option D

Answer is C

Explanation:

The moon and sun have their own gravitational pulls that indeed cause high and low tides. If you can see the moon over you at a beach for say, then the tides would be high, if there is no moon, then the tides are low

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.