答案:人 spend 时间/钱in doing sth.: We spend three hours commuting every day. 我们每天花三小时通勤。人 spend 时间/钱on sth.: We spend three hours on commute every day. 我们每天花三小时通勤。人 pay 钱 for 物: I pay three dollars for this pencil. 我付了三美元买这支铅笔。物cost 人 时间/钱: This pencil costs me three dollars. 这支铅笔花了我三美元。