make or become stronger 加强,巩固;使坚强;变强 [with obj.]he advises an application of fluoride to strengthen the teeth. 他建议使用氟化物来强固牙齿。 [no obj.]the wind won't strengthen until after dark. 风在天黑后才会变强。
常用词组 strengthen someone's hand (或 hands)
enable or encourage a person to act more vigorously or effectively 使做事更强硬;使行动更有力