We’d better set off，or it will be dark         we know it.

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

We’d better set off，or it will be dark         we know it.

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

We’d better set off，or it will be dark         we know it.

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

We’d better set off，or it will be dark         we know it.

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