题目内容：
Directions: Each sentence below has one or two blanks, each blank indicating that something has been omitted. Beneath the sentence are five lettered or sets of words. Choose the word or set of words for each blank that best fits the meaning of the sentence as a whole.In contemporary usage, continents are understood to be large, continuous, __________ masses of land, for they are almost always separated by expanses of water.
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