Sulfa drugs, such as antibiotics that contain sulfonamides. Example: Some combination drugs such as Sulfamethoxazole-trimethoprim (Septra, Bactrim) and Erythromycin-sulfisoxazole contain sulfonamides. <span>
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Answer:
Light travels in straight lines.
Explanation:
Once light has been produced, it will keep travelling in a straight line until it hits something else.
 
        
             
        
        
        
<span>The atomic mass is the number of protons plus the number of neutrons in an atom.</span>
        
             
        
        
        
Answer:
Observers ahead of the wave observe an apparent increase in wave frequency  
Explanation:
This is the Doppler Effect. The frequency of a wave increases when the source approaches the observer and decreases as the source recedes.
B, C, and D are wrong. Observers behind the source notice a decrease in frequency.