instruction:
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.
question:
original sentence: The sun was covered by a thick cloud all morning , but luckily , by the time the picnic started , it was out . paraphrase: the sun was covered by a thick fog all morning , but luckily , by the time the picnic started , it was out .
answer:
Synonym


question:
original sentence: This book introduced Shakespeare to Goethe ; it was a fine selection of his writing . paraphrase: This book introduced Shakespeare and Chaucer to Goethe and Marx ; it was a fine selection of their writing .
answer:
Number


question:
original sentence: Thomson visited Cooper's grave in 1765 . At that date he had been dead for five years . paraphrase: Thomson is visiting Cooper's grave in 1765 . At that date he has been dead for five years .
answer:

Tense