Most older antimalarials have been rendered useless by drug resistance.
耐药性已使多数较陈旧的抗疟药物失去效用。
2
Unlike previous antimalarials that have been rendered useless in many regions due to drug resistance, Artemisinin Combination Therapies (ACTs) are now recommended.
与在许多地区由于耐药性而无效的以前各种抗疟药不同，目前推荐使用以菁蒿素为基础的联合治疗药物。
3
Insect resistance to Bt would do irreparable harm, not just to genetically modified crops, but to organic crops as well, because Bt sprays would be rendered useless.