在关系模型中，把数据看成一个二维表，每一个二维表称为一个 【4】 。

Mr. Black loved his daughter very much. Every day he spent all of his free time  1____ with her. One night, he had much work to do , 2____ couldn’t play with his daughter. In order to keep her 3____he found a map of the world in a magazine and cut it into pieces. When he 4___ , Helen came running to him and was ready to play. Mr. Black said he had 5_____ time to play right now. He told the girl to put the pieces of paper back together to a map of the world, and then they could both play.
About half an hour later, Helen came to her father and said,“ Okay，it’s finished. Can we play now?” Mr. Black was surprised, saying, “That’s 6____. Let’s go and see.” And sure enough, there was the picture of the world, all put together, every 7____in its place. Mr. Black said, “That’s surprising! 8_____ did you do that?” Helen said, “It was 9____ .On the back of the page was a picture of a 10_____. When I put the man together, the whole world fell into place.”

小题1:	A．working B．running C．playing D．walking

小题2:	A．or B．and C．but D．then

小题3:	A．sleepy B．warm C．free D．busy

小题4:	A．left home B．got home C．left the office D．got to the office

小题5:	A．no B．enough C．much D．some

小题6:	A．right B．wrong C．possible D．impossible

小题7:	A．map B．picture C．piece D．page

小题8:	A．How B．Why C．When D．What

小题9:	A．hard B．simple C．difficult D．different

小题10:

A．boy B．girl C．man D．woman