下列离子方程式书写正确的是
A．在强碱溶液中次氯酸钠与Fe(OH)3反应生成Na2FeO4：
3ClO－＋2Fe(OH)3 ="2" FeO42－＋3Cl－＋H2O＋4H＋
B．4mol/L的NaAlO2溶液和7mol/L的HCl等体积互相均匀混合
4AlO2－＋7H＋＋H2O＝3Al(OH)3↓＋Al3＋
C．向NaAlO2溶液中通入过量CO2 2AlO2－＋CO2＋3H2O = 2Al(OH)3↓＋ CO32-－
D．NaHSO4溶液中滴入Ba(OH)2溶液至中性：H++SO42-+Ba2+十OH-=BaSO4↓+H2O
答案：B
A错，强碱性溶液中不可能生成氢离子；B正确；C错，正确为：AlO2－＋CO2＋2H2O = Al(OH)3↓＋ HCO3-－；D错，正确为：H++2SO42-+2Ba2+十OH-=2BaSO4↓+H2O；
When your mother want to tell you something, she uses words. Birds can’t speak 1._____ we do, but some birds can make sounds to warn their young of 2._______.They have 3.________own way of making the young birds do certain things. The jackdaw is a kind of black bird4.______lives in Europe. Jackdaws live together in flocks. Young jackdaws do not know their enemies. When an old jackdaw sees a dog, it makes a loud rattling5.______.The young birds know this sound means6._______is nearby. The sound warns them7._______their enemies. 8._______ a young jackdaw is in a 9______ place, a jackdaw parent 50._______over the young bird’s back from behind. The parent’s tail feathers move 11.______from side to side. It’s trying to say “12______”.At the same time, the 13.________bird calls out Key-aw Key-aw, which seems to say FLY HOME WITH ME. The young bird then follows the older14_______to go home. Young jackdaws15._______ learn what certain sounds mean. They know the meaning of these sounds from they hatch.
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