()Look!Somemeat____inthebox.Someapples_____inthebasket.

swim_______(现在分词)

足球比赛时，裁判用抛硬币猜正反面的方法让双方决定谁先要场地，谁先要发球权.这种做法是________的，因为________.

阅读理解，根据短文内容判断正(T)误(F)。

It'sSundaymorning.ThestudentsofClass3aregivingtheirclassroomagoodcleaning.

MissHuang,theirteacher,isworkingwiththem.Thechildrenarebusy.Somearecarryingwater;

somearecleaningthewindows;othersaresweepingthefloor.ZhangHuaisputtingupamaponthe

wall.ItisamapofChina.WangFeiandWeiQingaremendingsomebrokenchairs.Thechildrenare.

listeningtotheradiowhiletheyareworking.Theclassroomlooksniceandbrightafterthecleaning.

Thechildrenareveryhappy.Theygohomeforlunchatnoon.

()1.ThechildrenareplayingintheirclassroomonSundaymorning.

()2.MissHuang,theirmother,isworkingwiththem.

()3.ThereisamapofChinaonthewall.

()4.Twoofthemarerepairingthebrokenchairs.

()5.Theyaresingingwhiletheyareworking.

有①氨水②NH4Cl溶液③Na2CO3溶液④NaHCO3溶液各25mL，物质的量浓度均为0.1mo1/L，下列说正确的是