As of 1973, the US had a population of 210, million people, who were increasing by 0.8% per year. etc.
<u>Answer</u>:
Present Perfect Continuous: "I have not been allowing this to happen."
<u>Explanation</u>:
Present Perfect Continuous Tense indicates that something started in the past and is continuing at the present time.
<span>It is a group of words with a subject and a verb that provide a description of the word.It usually starts with a pronoun.
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