green bulwarks绿色壁垒
trade bulwarks贸易壁垒
pigsty bulwarks格子舷墙
technique bulwarks技术壁垒
Stairs and bulwarks梯及舷墙
pigsty bulwarks detail格子舷墙
green bulwarks problem绿色壁垒问题
N-COUNT（可数名词） A bulwark against something protects you against it. A bulwark of something protects it. 防护; 堡垒 [oft N 'against/of' n]
The abbeys were founded in the 12th century by King David as a bulwark against the English.
这些修道院是大卫王于12世纪修建的抵抗英国人的堡垒。