“天上星星有几颗，7后跟上22个0”，这是国际天文学联合会上宣布的消息，用科学记数法表示宇宙空间星星颗数____ 

已知M={a，a+d，a+2d}，N={a，aq，aq²}，a≠0，M=N，求q的值．

从方框中选择适当的单词完成短文。

   What's this on the table? It is a ____  of my new classroom. ____  at the picture. ____  can you see ____  the classroom? I can see a ____  desk in the front of the classroom. Some books are ____  the desk. I can see two white ____ , too. There are____  colored chalks (彩色粉笔n them. ____  is the broom (扫帚)? It’s ____  the door. I like this new classroom.