Answer:
B setting up a series of items in a list
Explanation:
Dr. Ronald Shaw, HER COLLEAGUE, concurs with the theory of a black hole at the galactic center of the milky way. The appositive phrase in this sentence is "her colleague" and this refers to the noun "Dr. Ronald Shaw". An appositive phrase consists of words that serves as an additional information about the noun it describes. Usually, appositive phrases are enclosed with a pair of commas.
Answer:
yesterday I was very happy because of starting our online classes in lockdown