神仙鱼左倾45
有必要的necessarynecessary 英[ˈnesəsəri] 美[ˈnesəseri] adj. 必要的; 强制的; 必然的; 不可避免的; n. 必需品; [例句]I kept the engine running because it might be necessary to leave fast我没让发动机熄火，因为也许需要迅速离开。[其他] 复数：necessaries
thomas0488
必要时的英文：at a pushIf it comes to the pinchin necessityon occasion参考例句：If appropriate, the environmental conditions shall be controlled and/or monitored.必要时,环境条件应予以控制或监控。If necessary, nylon, acrylic and polyester fibers may be bleached with sodium chlorite under acidic conditions.在必要时,尼龙、丙烯腈、涤纶纤维可在酸性条件下用氯化钠漂白。They were ready to die, if necessary, for their country.
