He kept close to Sandra and comforted her, saying this was the only choice they had and that things would be fine.

comforted 是动词 comfort 的过去式。comfort 由前缀 com-（表示"共同、加强"）和词根 fort（源自拉丁语 fortis，意为"坚强"）组成，字面意思是"使坚强"，引申为"安慰、抚慰"的意思。comforted 在这里表示"安慰"的动作已经发生。