<span>Its the first sentence choice:
1. Such a class you must have, or you would not have that other class which leads progress, civilization, and refinement.
</span><span>2.We use them for our purpose, and call them slaves.
</span><span>3.The highest proof of what is Nature's law.
</span><span>4.I will not characterize that class at the North by that term; but you have it; it is there; it is everywhere; it is eternal.</span>
<span>Noise, in communication, refers to the hinderance or interference between the transmission or interpretation of messages during the communication. Noise is of four main types; physical noise, psychological noise, semantic noise and physiological noise.Semantic noise refers to ambiguity in words, sentences and symbols, and may be caused due to someone's accent. The answer is B.</span>
