Answer:
B
Explanation:
Stratosphere,absorbs rays of damaging ultraviolet light from the sun 
 
        
                    
             
        
        
        
Answer:
Is the benefit worth the cost?
Explanation:
Environmental policies application has to lead to some economic cost.
When coming up with this policies, the effect that this policies shall have towards environmental protection shall be considered.
The cost and economic effect that this policies shall cause should also be looked at.
If a policy causes insignificant change towards environmental protection and at the same time the costs are too high, then the policy should be dropped.
If a policy has got significant impact and costs less, the it should be taken.
 
        
                    
             
        
        
        
The organisms which appeared on earth first was bacteria.
<u>Explanation:</u>
- The first-ever living organism on Earth was a bacteria known as cyanobacteria. It is believed by scientists that it first formed around 3 billion years ago. 
- When the Earth was first formed, it was inhospitable for a long time until 3.8 billion years ago approximately, the core cooled down and the level of oxygen had risen. This, along with photosynthesis resulted in the formation of Cyanobacteria. 
- These organisms were capable of carrying out the process of photosynthesis by which they prepared their food. These were known as common ancestors. All the living organisms thereafter are known to be their descendants.
 
        
                    
             
        
        
        
The appropriate answer is C. ANCESTRAL FINCH. The study of these birds on the Galapagos island led to Darwin proposing his theory of natural selection. Darwin collect and preserved samples of the finches he observed while on his travels. 
He did not observe anything unique about the birds until after he returned home. He focused on the differences in the beaks of the birds. It is then that he started to work on his revolutionary theory.
        
                    
             
        
        
        
The answer is penicillin
Rheumatic fever is a disease that caused by Group A streptococcus infection. The bacteria has component that similar to the heart valve cells, makes the immune cell attack it. The drug of choice for this infection is penicillin G benzathine injection. It is one of penicillin family drug that has high prevalence of allergy reaction, so you must be aware.