国际奥林匹克委员会已经决定第31届奥运会于2016年在里约热内卢举办。这个组织的英文简写是_________.

---Is this your book ? ---No , I think it’s ______ . 

 Look! There are some________ on the floor.

If you have a toothache, you should see a            .

 –What do you think of this ________?–I love it. I learned a lot about Steve Jobs after reading it.