strap someone in
phrasal verb with strap verb [ T usually + adv/prep ] uk/stræp/ us/stræp/ -pp-
为（某人）系好安全带
to fasten a seat belt around someone in a car, aircraft, or other vehicle, for safety purposes
Are you kids strapped in back there? 孩子们，你们在后面系好安全带了吗？