这次活动的成功取决于良好的规划。

The ___success of this event depends on good planning.

我试着给他打了好几次电话，但都没成功。

I tried to call him several times, but without ___success.

尽管到处都找遍了，我还是没能找到丢失的钥匙。

Despite searching everywhere, I found the missing keys with no ___success.