Use the required form of the infinitive in brackets. 17.She's like a beautiful exotic flower that must (to shelter) from bitter winds.18.This meeting, Edwina realized, must (to plan) several hours ago. 19. He seemed (to weigh) something in his mind. 20. He seemed (to take) his defeat quietly.21.I rang the bell of the dependable family, and the man answered with remarkable promptness; he seemed (to wait) for it to ring