这不是你的错，是系统出了问题。

It's not your ___fault; the system had an issue.

这不是你的错，是系统出了问题。

It's not your ___fault; the system malfunctioned.

科学家们正在研究这条断层带的地震活动。

Scientists are studying the earthquake activity along this ___fault line.

电脑无法启动是因为硬件故障。

The computer won't start due to a ___fault in the hardware.

他的第一次发球失误了，必须重发。

His first serve was a ___fault, so he had to serve again.