At the Copenhagen conference, all the countries were called on to do all they could to control greenhouse gas emissions________it was too late.

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

At the Copenhagen conference, all the countries were called on to do all they could to control greenhouse gas emissions        it was too late. w ww.ks 5u.co m

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

At the Copenhagen conference, all the countries were called on to do all they could to control greenhouse gas emissions ______ it was too late. w ww.ks 5u.co m

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

At the Copenhagen conference, all the countries were called on to do all they could to control greenhouse gas emissions________it was too late.

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

At the Copenhagen conference, all the countries were called on to do all they could to control greenhouse gas emissions        it was too late. w ww.ks 5u.co m

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