. I have taught hundreds of students,___________ having been working in their fields for years.

A.some of whom      B.some of them      C.most of whom     D.who

--- Have you gone over what the teacher taught in class?        

--- Not yet.

--- Better remember: ________.

I have taught hundreds of students,___________ having been working in their fields for years

1. A.
   some of whom
2. B.
   some of them
3. C.
   most of whom
4. D.
   who

---Have you been working in N0.5 Middle School since you graduated from college?

---No, I _______ in the countryside for 3 years.

1. A.
   have taught
2. B.
   had taught
3. C.
   have been teaching
4. D.
   taught

---Have you been working in N0.5 Middle School since you graduated from college?
---No, I ______ in the countryside for 3 years.

1. A.
   have taught
2. B.
   had taught
3. C.
   have been teaching
4. D.
   taught