abbr.

名词

电话商务

电话商务

1. （学科等的）基础知识，入门
The ABC of a subject or activity is the parts of it that you have to learn first because they are the most important and basic.

2. 字母表（儿童识字、写字、拼词用的全部字母）
Children who have learned their ABC or their ABCs have learned to recognize, write, or say the alphabet.