These problems, _______ will seriously affect the growth of teenagers and even the nation’s future.

A. not if solved properly                      B. if solved properly

C. not if properly solved                      D. if not solved properly

These problems, __________, will seriously affect the growth of teenagers and even the nation’s future.    

A. solved properly          B. if solved properly

C. not if properly solved     D. if not solved properly

These problems, ________ will seriously affect the growth of teenagers and even the nation’s future.

  A. not if solved properly B. if solved properly C. not if properly solved D. if not solved properly

These problems,   , will seriously affect the growth of teenagers and even the nation’s future.

A．not if solved properly                                   B．if solved properly

C．not if properly solved                                  D．if not properly solved

These problems, __________, will seriously affect the growth of teenagers and even the nation’s future.