下列反应的离子方程式书写中，正确的是（ ）
A：硫酸与氢氧化钡在溶液中反应：Ba2++SO42-= BaSO4↓
B：用Cl2将苦卤中的Br-氧化：Cl2 +2Br-= 2Cl-+ Br2
C：BaCO3与盐酸反应： CO32-＋2H＋ = H2O＋CO2↑
D：少量金属钠投入到CuSO4溶液中： 2Na＋Cu2＋= 2Na＋＋Cu↓
已知人的有耳垂（A）对无耳垂（ a）为显性．某家系三代6人的耳垂遗传情况如表．下列判断中正确的是（ ）
祖父
祖母
儿子
儿媳
孙子
孙女
有耳垂
无耳垂
Today is Children's Day.The students are in the park.There's a hill and a lake in the park.Now it's lunchtime.They're having a picnic on the grass.Zhang Tao is having a hamburger,Li Ming is eating a hot dog, Wang Lan is drinking some orange juice.They are going to to go skating after lunch.They can't find Su Hai and Su Yang.Oh,they're flying kites over there.All the students are very happy.
