本定义同时表明协议可能是口头的或书面的.The definition also indicates that agreement may be oral or written.诽谤和流言的区别在于前者是书面的,尔后者是口头的.The difference between libel and slander libel is printed slander is spoken.撤销可以是口头的,也可以是书面的.Revocation can...

“书面的”的英语可以翻译为：written ...