effort可数吗精力

　　例句：

　　They laughed at my puny efforts.

　　他们嘲笑我微不足道的努力。

　　All our efforts were in vain.

　　我们的所有努力都付诸东流了。

　　Their efforts were unavailing.

　　他们的努力都付诸东流。

　　Efforts to preserve the peace have failed.

　　维护和平的努力失败了。