D．How a tornado forms.

　　解析：　推理判断题。由第三段中最后的it is important to know where to hide and how to protect yourself in the face of a tornado可知，作者接下来很可能谈论在龙卷风来临时如何保护自己，故选B项。

　　答案：　B

　　Ⅲ.完形填空

　　 "Fire！Fire！" What terrible words to hear when I__1__in a strange house in the middle of the night！It was a large，__2__house-the sort that burns easily-and my room was on the top floor.I jumped out of bed，__3__the door and stepped out into the passage.It was full of __4__.

　　I began to__5__，but as I was still only half awake，__6__ going towards the stairs I went in the opposite direction.The smoke grew thicker and I found it hard to__7__.The floor became __8__under my feet.I ran into another room and tried to reach the__9__for fresh air.Suddenly，one of my feet got caught in something __10__and I fell down.The thing I had fallen over felt like a package of clothes，and I picked it up to protect my__11__from the smoke and heat.Just then the floor __12__under me and I fell through to the floor below with pieces of __13__wood all around me.

　　__14__，there was a doorway in front，so I put the package over my face and ran.My feet were terribly burned，but I__15__.As I reached the cold air outside，my package of clothes gave a __16__.I nearly dropped it in my surprise.Then I saw there were many people in the street.A woman screamed (尖叫) as she saw me and came running __17__.

　　"My baby！My baby！" she cried.Those people cheered loudly __18__she took the smoke­blackened package out of my arms.I almost__19__to see who she was-my boss's wife.I had __20__her baby，and become a hero!

　　语篇解读　本文是记叙文。作者主要讲述了自己经历的一次火灾。

　　1．A.hung up　　　　　　 B．called back

　　C．woke up D．turned back

　　解析：　由该空后的in the middle of the night以及下文的I jumped out of bed可知，作者听到有人喊"着火了！着火了！"就"醒来(woke up)"了。

　　答案：　C

　　2．A.clean B．empty

　　C．strong D．wooden

解析：　由该空后的the sort that burns easily可知，这是一座很大的"木制(wooden)"房屋。