.—— You finally made it , didn’t you ? ——Yes , ____your help , I would have not succeeded

25 Thirty years ago this month，China’s leaders launched aneconomic revolution___________the door to free market reforms and foreigntrade

The best way to learn new words is by _____ English magazines.

Many difficulties have____ as a result of the change over to a new type offuel. [ ]

下列各句中划线的成语使用恰当的一句是（ ）