operation作为手术可数吗

The system has been in operation for six months.

这个系统已经运行六个月了。

The operation could prolong his life by two or three years.

这次手术可使他多活两三年。

His quality of life has improved dramatically since the operation.

手术后他的生活质量大大改善了。

The new rules come into operation from next week.

新规定从下周起实施。

Will I need to have an operation?

我需要动手术吗？