国际电报电话咨询委员会和国际标准化组织为此进行了数年的研究工作。

Years of work have been carried out by the International Telegraph and Telephone Consultative Committee.

youdao

国际电报电话咨询委员会和国际标准化组织为此进行了数年的研究工作。

Years of work have been carried out by the International Telegraph and Telephone Consultative Committee.

youdao