The problem is that his grades aren't very good.
在这段话中，谈话者没有直接说出的含义是：
a glib talker, salesman, etc
油嘴滑舌的谈话者、 推销员等
pompous or pretentious talk or writing.
虚夸或者矫饰的谈话或者文字。
Someone who takes part in a conversation, often formally or officially.
对话者参加谈话的人，通常是正式地或官方地
INTERVIEW WITH THREE CORRESPONDENTS FROM THE CENTRAL NEWS AGENCY, THE SAO TANG PAO AND THE HSIN MIN PAO [1]
和中央社、扫荡报、新民报⑴三记者的谈话
TALK WITH THE AMERICAN CORRESPONDENT ANNA LOUISE STRONG
和美国记者安娜·路易斯·斯特朗的谈话
Talk with the American Correspondent A. T. Steele
和美国记者斯蒂尔的谈话
The Queen granted a few moments' conversation to her admirers
女王恩准与她的爱慕者们谈一会儿话。
Deerslayer listened to this characteristic message.
打鹿者倾听着这般激昂的谈话。
a secret listener to private conversations.
私人或秘密谈话的秘密收听者。
Analysis on the Fusion and Creation of Ye Shengtao s Fairy Tale;
开创者的脚步—谈叶圣陶童话的融创性
Re-read Mao Zedong s "talk with music workers ;
重读毛泽东《同音乐工作者的谈话》
Questioning Skills of Broadcasting Journalists in Collecting and Recording
广播记者采录人物谈话时的提问技巧
A conversation, such as one conducted by a reporter, in which facts or statements are elicited from another.
访谈谈话，例如由记者进行的访谈，由此从他人处获得事实或陈述
So how do you know whether you are talking to a Feeler, a Sensor, a Thinker, or an Intuitor?
如何知道谈话对方是感受者，感应着，直觉者还是思考者呢？
authors who plug their latest Books on TV talk shows.
在电视谈话节目中为他的新书宣传的作者
The systematic items stem from the walker's talk about the chalk.
这些系统的条款来源于步行者关于粉笔的谈话.
I have a rough understanding of the protocol involved when speaking with journalists.
对于和记者谈话时的有关协议我有粗略的了解