—We all had a lot of fun at the barbecue yesterday. Pity you weren’t there.

— I really should have gone with you, but I ________ on some remaining problems.

A．was working

B．would work

C．worked

D．had worked

数据是信息的符号表示，称为载体；信息则是数据的内涵，是数据的( )。

A．语用说明

B．语法解释

C．语义解释

D．用法说明