B: The emergency <em>lights</em> atop the fire trucks <em>were</em> flashing. Lights is your noun and were acts like your verb.
for A it should be: The exhibits on the lower level are not currently open to the public.
for C it should be: That man, wearing sunglasses, seems to be an undercover police officer.
for D it should be: Perry, like his younger sister Pauline, writes very neatly.
Hopefully this helped and good luck.
Answer:
so that students won't go out or won't go far. also it helps students grab snacks easily specially when they're hungry
the helpers were brave enough to make friends with the new person annie.