Question

1.She is a nurse with who / whom I enjoy working.
A) who
B) whom
2.Then 50 cc of Marcaine was / were injected.
A) was
B) were
3.Then 50 cc of Marcaine was / were injected.
A) was
B) were
My answers:
1.b
2.a
3.b

Answer 1

2 and 3 are the same. It's strange that you didn't catch that -- and answered each one differently.