“合用的”用英语怎么说

那些旧掸子来掸汽车上的灰倒挺合用的.Those old dusters will become useful for polishing the car.在找到,种合用的材料之前,他竟试验了两千种以上的材料.He tested over two thousand materials before discovering one that would work.食品协会已经出版了一本合用的手册.The Food Association h...