单项选择。—Inmyopinion，notallinventionswereinventedby

问题详情：

单项选择。

—In my opinion，not all inventions were invented by ________ accident.

—Well，you do seem to have ________ nting needs much time and hard work.

A．an；a  B．an；the  C．/；a  D．/；the

【回答】

C

知识点：冠词

题型：选择题