With more forests being destroyed, huge quantities of good earth ________ each year．

1. A.
   is washing away
2. B.
   is being washed away
3. C.
   are washing away
4. D.
   are being washed away

With more forests being destroyed，huge quantities of good earth ________ each year.

With more forests being destroyed, huge quantities of good earth __________ each year, which __________ that our environment is suffering.

With more forests _____being destroyed, huge _____ of good earth _____ washed away each year.

A. are ; number ; is  B. / ; quantities / are

C. be ; number ; are  D. / ; quantities ;is