If we can keep _____  this speed, we'll arrive there in two or three hours.

A. on   B. to    C. up     D. at 

If we can keep _____  this speed, we'll arrive there in two or three hours.

1. A.
   on
2. B.
   to
3. C.
   up
4. D.
   at

 If we can keep ____  this speed, we'll arrive there in two or three hours.

A. on   B. to    C. up     D. at