For each of the following items, write a regular expression which matches the specified text (including but not limited to all of the underlined phrases in each example) and no other text in the given line, assuming that your expression is intended to be used with grep. For these items, you may not simply list an underlined phrase itself; you must use at least one special character in each answer. Note: the string following each item is just provided for illustrative purposes. Therefore, do not write a regular expression which matches the underlined strings only in the sample sentence.

  1. Matching "Hello", "hi", or "howdy":
    Hello, there.  Or is "hi" or "howdy" more to your liking?
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  2. Matching "the", regardless of case:
    The quick brown fox jumps over the lazy dog.
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  3. The last word in a sentence:
    How many sentences are here? There are two.  No, three!
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  4. A social security number:
    Match the number 045-35-2344 but not 045-3-52344.
  5. A word with five or more letters:
    This sentence does not have many long words.
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  6. Any proper noun:
    Jean-Luc, Worf, and Q, but not wormhole jump.
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  7. An entire sentence that ends in a period:
    Does this sentence end in a period?  This one, indeed, does.
  8. Any sequence beginning with "artificial" and ending with "intelligence":
    Politicians can act artificial, but do they have intelligence?
  9. Any of "computer", "computers", or "computing":
    computer science is the study of computing, and how computers work.
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  10. Matching any phrase of exactly three words separated by white space:
    This is a short sentence.