在下列词中的可数名词前加a或an,不可数名词加/1.grass2.milk3.idea4.law5.meat6.music7.medicine8.plant9.progress10.programme11.homework12.shoe13.season14.tennis15.travel16.trip17.water18.biscuit19.event20.eyesight21.ho

　　在下列词中的可数名词前加a或an,不可数名词加/

　　1.grass2.milk3.idea4.law5.meat6.music7.medicine8.plant

　　9.progress10.programme11.homework12.shoe13.season14.tennis

　　15.travel16.trip17.water18.biscuit19.event20.eyesight21.housework22.postage23.record24.sause25.shampoo26.steam

　　27.whale28.turkey29.vapour30.air31.loaf32.kindness33.geography34.flour