The answer is simile due to the use of like
Not only should the children should be taking care of the Grandparents. Everyone should be taking care of everyone. That's how family works. They should be because, the Grandparents would (should) do the same.
Jellyfish swim in groups and are causing ecological issues and health threats to people, but people are finding different ways to fix these problems
He's (A).. -already- finished his essay
What are you gonna do? I dont know I haven't decided (D).. -Yet-
I've (A) -Been- to london
Have you (A) -ever- done any skiing?
My boyfriend hasnt rung (A) -for- a week.