他从多次失败中吸取了教训，最终获得了成功。

He learned valuable lessons from his ___failures before finally achieving success.

这些实验中的大多数都因设备故障而成为失败案例。

Most of these experiments turned out to be ___failures due to equipment malfunctions.

频繁的发动机故障导致航班延误。

Frequent engine ___failures caused flight delays.