401. One indisputable fact is that..., and this trend is expected to continue into the future. There are two main reasons for this phenomenon.
一个不容置疑的事实是……，这一趋势还将延续到未来。导致这一现象的主要原因有两点。

六级词汇讲解:
该句可作为分析原因或现象的议论文的第一段。第一句中的one indisputable fact is that...通常用在第一段或主体段的段首，其后接表语从句，以引出一种事实或现象。indisputable意为“无可争辩的，不容置疑的”。be expected to意为“被期望做某事”，含有“在意料之内”的意思。在指出了全文的中心之后，最好明确交代下文中所分析的原因的数量，如上句中的There are two main reasons for this phenomenon.

句型拓展:
The indisputable fact is that you were late for the meeting yesterday.
不容置疑的是，你昨天开会迟到了。
It is an indisputable fact that second-hand smoke is harmful for everyone.
无可争议的是，二手烟对每个人都有害。
No one can deny the fact that the new policy took effect in the short run.
无可否认的是，从短期看来，新政策起效了。