"You" does not agree with "one's." When using "one" as a pronoun to speak about an assumed general person, remember not to lapse into using the pronoun "you."

This sentence uses “one” and “you” interchangeably. These should stay consistent. The corrected sentence reads, "One must understand that even if it seems like one’s life will never be affected, an alien abduction could happen to anyone."

"One" should be used in place of "you" in this sentence. When a setence is referring to a person nonspecifically in reference to an action, "one" should be used because "you" is a more direct pronoun used for talking directly to someone. Plus, "one" is used later in the sentence, and it is not correct to switch to using "one" in place of "you" (or vice-versa) in mid-sentence. So, "you" contains the error.

The pronouns in a sentence must agree. If you use "you" to refer to one person, you cannot use "one" to refer to the same person in the same sentence.

In this sentence, the generic/impersonal pronouns are used to give general advice to anyone rather than some person in particular. Both "you" and "one" are considered appropriate impersonal pronouns, but they must be used consistently for a sentence to be grammatically correct. In the above sentence, either the instance of "you" should be changed to "one" or the instance of "one" should be changed to "you," but only "one" is underlined, so that is the only correct answer.

This sentence's error occurs in the phrase "as it matured." Since Billy the cat is referred to as "he" in the rest of the sentence, it doesn't make sense to suddenly refer to him as "it" in this phrase. Changing "it" to "he" would correct the sentence's error.

Because the singular pronoun "one" is used to describe the subject at the beginning of the sentence, the plural pronoun "they" cannot be used to describe the same subject. Therefore, in order for the sentence to be correct, "they should," would have to be replaced with "one should."

The error in this sentence has to do with using both "one" and "you" as pronouns in a single sentence. Once you being using one of these pronouns in a sentence, you should stick with it and not switch to using the other one in mid-sentence. This sentence's latter half begins with "one" and uses the phrase "as if one has walked," but near the end, it switches to using "you" when it says "when you step in the door." To correct this sentence's error, "when you step in the door" should be changed to "when one steps in the door."

In the first part of the sentence, the writer begins using the pronoun "one."  This usage should be kept consistent throughout the sentence, so the introduction of "your" is erroneous and should be corrected.

In the sentence above, "you" is used, as is "your." This is consistent usage of the same pronoun, and the sentence is correct as it is written.