改进后的皮碗式封堵技术经济效益和社会效益显著。

The improved sealing cup-type plugging technology has remarkable social benefit and economic benefit.

youdao

改进后的皮碗式封堵技术经济效益和社会效益显著。

The improved sealing cup-type plugging technology has remarkable social benefit and economic benefit.

youdao