Up to now, they _________ a good way to solve that problem.

1. A.
   didn’t find
2. B.
   can’t find
3. C.
   hadn’t found
4. D.
   haven’t found

Up to now nobody          able to do this better than Charlie Chaplin.

1. A.
   is
2. B.
   has been
3. C.
   was
4. D.
   will be

Up to now, the program ________ thousands of children who would otherwise have died.

   A. would save             B. saves

   C. had saved              D. has saved

Up to Tuesday's attack, the worst school shooting in the U. S. was in March 1998 in Jonesboro,________ two boys, aged 11 and 13, shot and killed a teacher and four girls.

     A. while         B. where       C. when        D. then

Up to Tuesday's attack, the worst school shooting in the U. S. was in March 1998 in Jonesboro,______two boys, aged 11 and 13, shot and killed a teacher and four girls.

A. while         B. where          C. when         D. then