defence against sth
+ disease, recession, attack防治某物；抵抗某物
The immune system is our main defence against disease.人体的免疫系统是抵御疾病的主要屏障。
Diversity is the best defence against recession.经营多元化是防止衰退的最佳手段。
They produce the venom as a defence against attack by predators.为了抵御掠食者的攻击, 它们会分泌毒液。