These trees are under the (watch) of my group.
Mrs Smith left her child under my (care) when she was out.理由捏？watch 这个词当名词用的时候经常和介词 under 连用，就有“照顾”、“照看”的意思。 under sb's watch在XX的照看、看管下the "Neighborhood Watch" program （邻里小区的“守望相助”） watch 的用法更常用在“事或物”，care 更多用于“人”。