When printing was being developed paper became the predominant material for books in Europe, but prior to that it was parchment.

当印刷术发展起来时， 纸张成为欧洲书籍的主要材料，但在此之前它是羊皮纸。

The still nascent field that Mr. Musk is looking to develop Mr. Musk's own paper on the topic sites Dr. Lieber as well as Chinese researchers who worked in his lab at Harvard.

马斯克先生正在寻求开发马斯克先生自己关于利伯博士以及在哈佛实验室工作的中国研究人员的主题论文的新兴领域。