题目：

I was cooking in the kitchen _______(as,that) he was coming in.

我做题的时候是这样的：因为我们只学过 as，所以选 as。

但是 that 放到句子中貌似也没啥问题。我用我的语感感觉 "he was coming in" 那部分的时态用 that 就会有问题。

有没有巨佬解答一下。违规紫衫。