The plants must be protected against frost until late spring.必须保护好植物免受霜冻，直到晚春。The plants should be protected against the cold.应该保护这些植物使之不受冻。People need to be protected against such unwarranted intrusions into their private lives by journalists.人们的私生活需要受到保护，免受新闻记者的无理侵犯。