Which were signed on December 10. 2012

Participial Phrase
A participial phrase contains a participle and its modifiers or complements. Remember that participles are verbs that end in –ing, -ed or –en (except for some irregular verbs). Participial phrases function as adjectives within a sentence.⁶
Example: The student sitting in the front row raised his hand to answer the question.
The sculpture, broken during the last earthquake, is no longer valuable.
You will notice that the participial phrase in the second example is set off by commas. This is because it is a nonrestrictive phrase. That means that, while it modifies sculpture and adds detail to the sentence, if the clause were removed the sentence would still have the same meaning.
Prepositional Phrase
A prepositional phrase contains a preposition, a noun or pronoun, and possibly one or more adjectives. Prepositional phrases can function as nouns, adjectives or adverbs within a sentence.⁷
Example: My birthday is on Monday.
The tree with the purple blossoms hangs over the sidewalk, sprinkling flowers along the path.
In the first example, on Monday functions as a noun and serves as a complement. In the second example, with the purple blossoms functions as an adjective modifying tree, while both over the sidewalk and along the path function as adverbs modifying hangs and sprinkling, respectively.
Absolute Phrase:
An absolute phrase most often contains a noun or pronoun, a participle, and modifiers; however, rather than modifying one single element of a sentence, absolute phrases modify the entire sentence. You’ll notice that absolute phrases (again, most often) have a subject modified by a participle but no verb. You can think of absolutes as “almost sentences” because adding “was” or “were” to most of them creates an independent clause. A second way to identify an absolute phrase is to look for a possessive pronoun (my, his, her, its, our, their) at the beginning of the phrase. You’ll find absolute phrases not only at the beginning of sentences, but also as subject-verb splits and sentence closers.⁸
Examples: His study habits thorough, Alex earned an A in the class.
Lauren, her mouth watering, waited for the pasta to cool before taking a bite.
The players staggered into the locker room defeated, their faces showing disappointment.
In the first sentence, the absolute phrase modifies the entire independent clause Alex earned an A in the class. Likewise, the absolute phrase in the second example also modifies the entire independent clause rather than one single element of it