It's FREEPOST, so there's no need for a stamp.这是免费邮寄，不用贴邮票。Reply to Publicity Department, FREEPOST, Oxford University Press, Oxford.回信免费邮寄至牛津牛津大学出版社宣传部....
在人类从事航空的初期,飞行员全凭直觉飞行.Pilots in the early days of aviation flew by the seat of their pants.顺利的航海仿佛也是航空的好预兆.The maritime passage was a good augury for the aerial passage.他们曾作为早期航空的先驱.They pioneered in early aviation....
The carbon is electrophilic centre.碳是亲电的中心.It will become deepen to the students'recognization in mechanism of Aryl electrophilic substitution.这些问题的讨论将深化学生对芳烃亲电取代反应机理的认识.The rate constants of radical and electrophil...