桰t's 9 o'clock now. I must go.　　

桰t's raining outside. Don't leave ________ it stops.

A. when

B. since

C. while

D. until

---It’s 9 o’clock now．I must go．

---It’s raining outside．Don’t leave ________it stops．

1. A.
   when
2. B.
   since
3. C.
   while
4. D.
   until

?It's 9 o'clock now. I must go.

?It's raining outside. Don't leave ________ it stops.

A. or

B. but

C. so

D. until