他的经验在危机中证明是极其有用的。

His experience proved ___invaluable during the crisis.

这次研讨会提供了关于现代技术的极其有用的见解。

The workshop provided ___invaluable insights into modern technology.

你的建议对我的职业发展极其有用。

Your advice has been ___invaluable to my career development.