请教个语法问题：定语从句关系代词that可以指代人吗？

一直以为是可以的，白勇语法上也说可以。

今天复习时，仔细看到OG上的解释，却说不可以，OG10的188题，也就是OG11的130题，如下：

As a result of medical advances, many people that might at one time have died as children of such infections as diphtheria, pneumonia, or rheumatic fever now live well into old age.

答案不用通过that也能解出来，但是OG解释里面说：

OG10:use the questionable relative pronoun that to refer to many people

OG11: The pronoun who, rather than that, should be used to refer to people.

That 在定语从句中究竟能不能用来指代人呢，请教各位兄弟姐妹了～

顶一下～

请教各位呀～

谢谢楼上的～

gamc认为that只能指代物了，跟一般的英语语法不同，算是gmac的观点是吧？嘿嘿，那就记下来。