Answer:
I think it is the last one.
Explanation:
I am not sure because i am stuck on this one, too.
Answer: C solar energy
Solar energy has the greatest impact on primary productivity.
Explanation:
Primary productivity is the amount of organic compounds synthesized from carbon dioxide. Primary production occurs by the process of photosynthesis. Since the process of photosynthesis uses sunlight as the energy source solar energy has the greatest impact on primary productivity.
The synthesis can occur in atmosphere as well as aquatic environment. The organisms that perform the function of primary production are called producers .In terrestrial regions plants are the producers and in aquatic systems algae are the primary producers.
Answer:
option D
Explanation:
given,
Intensity of sound = 20 dB
distance = 15 m
intensity of sound is increased to = 50 dB
distance between the sound level = ?
Using relation

L₁ = 20 dB L₂ = 50 dB r₁ = 15 m r₂ = ?





r₂ = 0.47 m
r₂ = 47 cm
hence, the correct answer is option D
Answer: 1 The correct answer is that CMB radiation was spread uniformly throughout the whole universe.This was related to big band theory because this theory predicts that the universe was a very hot place and as it cooled down it should have been filled with laterally the remnant heat over from the Big Bang called as cosmic microwave background.
Answer: 2 CMB radiation was discovered accidentally when Penzias and Wilson were performing some experiment and they noticed a ' hum' noise that was constantly detected by the antenna even after removing all the disturbing sources.
Then it was realized that it is cosmic microwave background radiation.