The first great invention was ___ that is still important---the wheel.

问题描述:

The first great invention was ___ that is still important---the wheel.
The first great invention was ___ that is still important---the wheel.
1.the one
2.one
这句是什么从句?请分析题目,

答案应选 2.one;
one 后省略了 invention,直接把下面两条句子组合成了复合句:
The first great invention was the wheel.
One invention that is still important (today) is the wheel.
组合后的句子也可以换种方式排列而意思不变:
The first great invention was the wheel,one that is still important.
这样就看得比较清楚成分:the wheel 是宾语,而 one 引导从句作为宾补.