A：先胰岛素溶液，后葡萄糖溶液
B：先胰岛素溶液，再胰岛素溶液
C：先胰岛素溶液，后生理盐水
D：先生理盐水，后胰岛素溶液
补全对话。
A．It's so big!
B．It's on the first floor．
C．No，it isn't．
D．Twenty．
E．Yes，we do．
It's around 500 metres from my home to school.
