---May I go and play with Tom this afternoon, Mum?

---No. You can't go out ________ your homework is being done.

1. A.
   until
2. B.
   since
3. C.
   before
4. D.
   if

--May I go and play with Tom this afternoon, Mum?

--No. You can't go out _____________ your homework is being done.

    A. before             B. as                  C. until               D. after

--May I go and play with Tom this afternoon, Mum?

--No. You can't go out _____________ your homework is being done.

A. before             B. as                  C. until               D. after

---May I go and play with Tom this afternoon, mum?

       ---No．You can’t go out ______ your homework is being done．

       A．until        B．after  C．before      D．as

---May I go and play with Tom this afternoon, mum?
---No．You can’t go out ______ your homework is being done．

1. A.
   until
2. B.
   after
3. C.
   before
4. D.
   as