Answer : False.
Explanation : Acid rain is the indirect result of burning fossil fuels. As the incomplete combustion of fossil fuels releases sulfur dioxide and nitrous dioxide in the air. When it rains it gets mixed with water and forms nitric acid and sulfuric acid which causes acid rain. Acid rain is harmful.
Answer:
Here the source is moving away from the observer so frequency will be smaller than the actual frequency and since the speed is increasing so the frequency is decreasing with time so correct answer is
D) lower than the original pitch and decreasing as he falls.
Explanation:
As we know by the Doppler's effect of sound we have
so we will have

so here when source moves away from the observer with a some speed then the frequency of the sound observed by the observer is smaller than the actual frequency
Here we know that the speed of the source is increasing with time as the source is falling under gravity
So we can say that the pitch of the sound will decrease with time
Answer:
people grow by the year sometimes it even by months
Answer: Stars are formed in clouds of gas and dust, known as nebulae. Nuclear reactions at the centre (or core) of stars provides enough energy to make them shine brightly for many years. The exact lifetime of a star depends very much on its size.
Explanation: I try to do your question, hope this help