When people cut down big trees, new trees should be planted．________, they will have no trees to cut down in the future．

1. A.
   If not
2. B.
   If so
3. C.
   If no so
4. D.
   If don't

When people cut down big trees, new trees should be planted． _______ they will have no trees to cut down in the future．

A． If not             B． If so             C． If no so          D． If don’t

When people cut down big trees，new trees should be planted．      ，they will have no trees to cut down in the future．

A．If not            B．If so         C． If not so                    D．If don’t

 (2011年濰坊質(zhì)量監(jiān)測)When people cut down big trees，new trees should be planted.________they will have no trees to cut down in the future.

A．If not                           B．If so

C．If no so                        D．If don’t