---- Here. Your new computer is ready. ----Thank you. ---- _______to call this number if you have any problems or questions. A. You are free B.It is free C. Feel free D.Don’t forget 答案:C 解析: :Feel free用以表示准许。下列图示的实验操作中,错误的是: A.吸取液体 B.称取一定质量的NaOH C.铁在氧气中燃烧 D.检查装置气密性