Answer:
1. The idea of alien life (proposed many years ago) has not yet been proven- Participle phrase.
The participle phrase starts either with the present   (dependably ending with -ing) or past   (dependably ending with -ed)
The participle phrase includes the modifiers or objects to complete the thought of the sentence.
2. (According to the letter) the wedding is June 25th.- Prepositional.
A prepositional phrase refers to the phrase which begins with a preposition and ends with the 'objects' of the prepositions that are nouns, gerund, clause or pronoun.
The pattern of the prepositional phrase follows by the object of the preposition having one or more modifiers.
3. Mikayla's homeroom teacher, (mr. Jones) is very proud of her- Appositive
Appositive refers to a word or a noun that is followed by another phrase or noun which identifies or rename the noun or word. In other words, it refers to the literary device which appears after or before a noun phrase or noun, used with a comma.
4. (Talking) is not allowed in class- Gerund
Gerund in a sentence functions as a noun. Hence in a sentence, a gerund will act as direct objects, subjects, subject complements, an object of prepositions or indirect objects. Every gerund ends in -ing, and so does present participles. On the other hand, present participles act as modifiers or complete progressive verbs.
Explanation:
 
        
             
        
        
        
Answer: an objective opinion is based on facts, and unbiased.Not influenced by personal feelings or prejudice. 
 
        
                    
             
        
        
        
so the answer is 15° 
the circle is 360° 
one green angle is 50°
so 4 green angles equals 200°
so 360 minus 200 equals 60.
so 60° angle. and as a result the rest of the angles are 60° of the circle. and so each of the angles are... 15° if the 60 is divided by 4.
 
        
             
        
        
        
<span>"His historical researches, however, did not lie so much among books as among men; for the former are lamentably scanty on his favorite topics; whereas he found the old burghers, and still more their wives, rich in that legendary lore, so invaluable to true history. Whenever, therefore, he happened upon a genuine Dutch family, snugly shut up in its low-roofed farmhouse, under a spreading sycamore, he looked upon it as a little clasped volume of black-letter,' and studied it with the zeal of a book-worm.""Rip Van Winkle," 1994 edition, 1-2
</span>
        
             
        
        
        
C. If they know you don't care then its less likely that critics will criticize your persuasive argument, or D will also work