The students were participating________an international energy?saving competition between towns in New England and Canada.

A．for B．in

C．to D．at

The students were participating ________an international energy-saving competition between towns in New England and Canada．

1. A.
   for
2. B.
   in
3. C.
   to
4. D.
   at

The students were participating_______ an international energy saving competition between towns in New England and Canada.

A. for             B. in             C. to            D. at

The students were participating __________ an international energy-saving competition between towns in New England and Canada.

A. for          B. in           C. to         D. at