There is no denying the fact that (why/how/what) ____________ is a hot topic which is much talked about [not only by ____________, but also by ____________ /by people across the world/ in a modern society].
或：There is no denying the fact that (why/how/what) ____________ is a popular topic which has caused heated debate over a long period of time (because it affects everybody in his or her daily lives).
或：There is no denying the fact that (why/how/what) ____________ is a basic (moral/philosophical) problem that can not be circumvented by anybody,( because the opinion on this problem will determine one’s attitude toward the world and the life).
或：（如果是针对某一事件的题目，不是什么popular topic）____________(Why people visit museums) is a interesting question that deserves careful investigation not only by_______________(museum managers), but also by ____________(visitors themselves). People with different experience, life style and [emotional concerns / educational background/____________] differ greatly in their attitudes toward this [problem /question]. Some people hold the opinion that ____________. Others, [however/on the contrary], maintain that ____________. Still others, convinced by the view that ____________, argue that ____________. According to them,____________. But as far as I am concerned, I consider the [chief reason/ most important quality] is ____________. And here are three reasons that I’d like to point out.