We often see dogs always put their tongues(舌头)out in summer. But 1 the dogs didn’t do so. Long long ago, the dog was very bad .He 2 did a good deed. One summer day the dog 3 into a forest. 4 he saw the forest was beautiful and clean ,  a 5 idea came to him. Then he brought 6 dirty things to the forest and put 7 everywhere. What he did was 8 by a monkey who hid 9 a big tree. He didn’t tell anyone 10 the dog did because 11 did not know why the dog did so. Several days 12   , it got hotter and hotter , and the dirty things became rotten(腐烂).The air smelt 13 . Many animals fell ill. All the other animals became angry and tried 14 who had done it and punish him. The money knew 15 bad the dog was. So he 16 the other animals the truth. They catch up with the dog and 17 him eat all the dirty things and 18 the forest clean. After that the dog 19 honest. To remember this, he put his tongue out in 20. 小题1: A．at last B．at least C．in the past D．first of all 小题2: A．never B．often C．for ever D．suddenly 小题3: A．entered B．arrived C．reached D．went 小题4: A．So B．When C．So that D．Once 小题5: A．good B．bad C．wonderful D．common 小题6: A．a lot B．a great many C．much D．a little 小题7: A．it B．that C．these D．them 小题8: A．looked B．caught C．watched D．seen 小题9: A．behind B．before C．around D．besides 小题10: A．how B．when C．what D．why 小题11: A．he B．him C．whom D．which 小题12: A．before B．ago C．later D．long 小题13: A．terrible B．nice C．badly D．clean 小题14: A．not to tell B．to find out C．not telling D．finding out 小题15: A．very B．what C．why D．how 小题16: A．said B．spoke C．told D．answered 小题17: A．wanted B．let C．allowed D．asked 小题18: A．keep B．let C．have D．make 小题19: A．wasn’t B．didn’t seem to be C．became D．went 小题20: A．spring B．summer C．autumn D．winter