[单选题]基于BIM技术的施工过程模拟指的是在施工现场3D模型的基础上引入()维度，从而对工程主体结构施工过程进行4D模拟。
A.时间
B.成本
C.荷载
D.材料

61 ) While there are almost as many definitions of history as there are historians, modern practice most closely conforms to one that sees history as the attempt to recreate and explain the significant events of the past. Caught in the web of its own time and place, each generation of historians determines anew what is significant for it in the past. In this search the evidence found is always in- complete and scattered; it is also frequently partial or partisan. The irony of the historian’s craft is that its practitioners always know that their efforts are but contributions to an unending process.
62) Interest in historical methods has arisen less through external challenge to the validity of history as an intellectual discipline and more from internal quarrels among historians themselves. While history once revered its affinity to literature and philosophy, the emerging social sciences seemed to afford greater opportunities for asking new questions