He seemed to be thinking, sketching out in his mind what he was going to say.他似乎在思考，就自己想说的话打着腹稿。As he reflected on his appalling behaviour, he mentally composed a letter of apology to his host.他一边反省自己的恶劣行为，一边打腹稿，给主人写道歉信。He sat there perusing until he was ready to speak.他坐在那儿一个劲儿地苦思冥索，直到打好腹稿准备发言。