A mirror is opaque because you cannot see through it
No, grandparents is a common noun, therefore you don't capitalize it. It would be different if you had the names of the grandparents. Like if your grandma is named Martha. You would have to capitalize their name since it is a proper noun
C. The noun or pronoun that identifies the person, place, or thing that the sentence is about.
Tentative means being unsure or hesitant. Hope this helps. <span />
