The young child protested that she didn't want to leave her mother.

protested 是动词 protest 的过去式，protest 由前缀 pro-（表示"向前、公开"）和词根 test（源自拉丁语 testari，意为"作证"）组成，本义是"公开声明"，引申为"抗议、反对"的意思。