1---31
1.用a或an填空

——orange     2.——exercise book  3.——unliversity      4.——question   5.——old man   6.—year
7.——ymbrella    8.——useful book  9.——artist    10.——idea  11.——english teacher  
12.——wrong answer  13.——japaneae  14.——island  15——interesting story  16.——honest child
2.用a.an或the填空
mr.smith lives in——town named gumtree.——town is very beautiful and clean.
l have ——lot of work to do this afternoon.
l can see ——animal in the tree.it look like ——monkey.
there are four seasons in——year.——first sesson i spring.it's——best one of ——four.