on or from the outside; "the candidate needs to be externally evaluated"
adverb [地点副词] 外部地；外表上，外形上
Vitamins can be applied externally to the skin. 维生素可以外用于皮肤。
external(表面的) + ly → 外表上， 外形上
Vitamins can be applied externally to the skin. 维生素可以外用于皮肤。