You will be given two sentences. One of them is created by paraphrasing the original one, with changes on an aspect, or using synonyms. Your task is to decide what is the difference between two sentences. Types of change are explained below:
 Tense: The verbs in the sentence are changed in tense.
Number: Plural nouns, verbs and pronouns are changed into single ones or the other way around.
Voice: If the verbs are in active voice, they're changed to passive or the other way around.
Adverb: The paraphrase has one adverb or more than the original sentence.
Gender: The paraphrase differs from the original sentence in the gender of the names and pronouns.
Synonym: Some words or phrases of the original sentence are replaced with synonym words or phrases. Changes in the names of people are also considered a synonym change. Classify your answers into Tense, Number, Voice, Adverb, Gender, and Synonym.
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Question: original sentence: John was doing research in the library when he heard a man humming and whistling . He was very annoyed . paraphrase: John is doing research in the library when he hears a man humming and whistling . He is very annoyed .

Answer: Tense


Question: original sentence: I took the water bottle out of the backpack so that it would be handy . paraphrase: I took the water bottles out of the backpacks so that they would be handy .

Answer: Number


Question: original sentence: Carol believed that Rebecca regretted that she had stolen the watch . paraphrase: Carol and Julia believed that Rebecca and Nancy regretted that they had stolen the watch .

Answer:
Number