【经】 保护贸易制

在风力侵蚀地区，应当采取开发水源、引水拉沙、植树种草、设置人工沙障和网格林带等措施，建立防风固沙防护体系，控制风沙危害。

protective coloration

protective

protective cage

reflective, protective layer

discharge tube having screen with conductive, reflective protective layers

electrothermal, circuit breaker protective switch

emergency protective circuit arrangement responsive to phase failure

circuit breaker, electrodynamic protective switch