烧伤并发应激性溃疡的主要机制不包括以下哪一项（）.

A.炎症介质对胃黏膜的损伤

B.胃黏膜血流量减少

C.胃酸分泌

D.糖皮质激素改变

E.黏膜屏障功能损伤

---The Bird's Nest, isn't it?

---Yes. It's ___________we visited during our stay in Beijing.

A．where

B．what

C．when

D．That