A MOOC is a massive open online courses. Believing the hype is something I cannot answer for you. It is an opinion, and it is yours to answer.
For the first question, item D is correct because you'll need to place a comma before and after parenthetical elements: "<span>The beach, which closes after Labor Day, has white sand."
For the second question, item D is correct because commas are only needed for a series of three or more elements; thus, no commas are needed: "</span><span>I bought a beautiful pitcher and eight glasses."
For the third question, there are no commas needed; thus, item A is the correct sentence: "</span><span>The music made me sleepy."
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For the fourth question, item C is the correct response because commas are needed after subordinate clauses that begin a sentence: "</span><span>As the band marched across the field, the crowd cheered."
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For the fifth question, item D is the correct response because in order to keep from having a run-on sentence a comma is always needed before a conjunction that is connecting two complete sentences: "<span>He works long hours, yet he keeps up with his studies."</span>
Answer:
Traffic was slow, so I should have taken the train.
Answer: ...we shall pay any price, bear any burden, meet any hardship.......
Explanation:
You put the comma here: Ricky has a job, but Wanda is unemployment.
Hope helps!-Aparri