打扰大伙了，我想问一下this和that是不同，这是在我做一道英语填空题的时候发现自己搞不懂this和that有什么区别，对此我纠结了很长时间。题目如下：
All decisions about who did what, how quickly and by when, were the responsibility of the whole group. It was found that groups of this type became very committed to the task and produced high-quality work.
我记得that是将上文的事，而this是指下文的事，所以我填了that，但答案是this，请大伙帮忙剖析。
that不能指代下文才提及的事情，但this则既能够指代前文的事，也可以指代下文才出现的事，并不是只能指代下文。
当说话人只提及一件事时，指示代词用近指代词this。比如：
I bought a book yesterday. This book is interesting. 而不是that book.
当说话人提及二个事物，后提及的事物用远指代词that指代。
The book you lent to me is easier to read than the one I borrowed from Tom. That book is not suitablefor me.