Assuming this is the paragraph:
"<span>Dogs and cats are both fantastic pets. Dogs are loving and playful. Cats are clean and self-sufficient. Dogs </span>are sometimes hyper. ___ <span> Both are effective communicators in their own right. Either one would </span><span>make any lucky owner happy,"
the correct answer is Cats are clean and self-sufficient.
In the paragraph, you are supposed to show why both dogs and cats are good pets. First you talked about dogs, which means you should mention something about cats too. This is why that is the correct answer.
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A statistical measurement of the average time a
person is expected to live is a life expectancy and it depends on many factors.
<span>These days we see some improvement in life
expectancy, this is because now medical health care has been improved. Death
rates from infectious diseases have fallen and life expectancy his improved and
the second thing is a healthy life style is very important for the improvement of life expectancy.</span>
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