It took some sixty million years to complete the move.

How long did it take the redwood to complete its long journey?

请问老师，原文句中the wood 是it的同位语吗？

不应该是 How long did the redwood take to complete its long journey?

主语为何重复出现？

【答】网友提供的两个句子，结构稍有不同。

第1句：It takes + some time + to do sth.

第2句：It takes + sb. + some time + to do sth.

两句中的it都是形式主语，不定式是真实主语。不同的是，第2句中的take 接了双宾语。

所以，the redwood 不是it 的同位语。此外，网友的这个句子：

How long did the redwood take to complete its long journey?

（主语是the redwood，不定式的逻辑主语也是the redwood，说明：这棵红衫木用了多久才完成了其行程，运到目的地？本句强调了红衫木自身的动作。）

请看下面的句型，以下表达都正确。

1. It took ten years to complete the great statue.

2. It took the sculptor ten years to complete the great statue.

3. The sculptor took ten years to complete the great statue.

4. The great statue took ten years to complete. （不过，在本句中，to complete 的逻辑主语是“人”， complete的宾语成了句子的主语the great statue，因此，意思上相当于for sb. to complete the great statue。但complete 是不能接宾语的。）