A:CH3COONa溶液中:c(OH-)=C(H+)+C(CH3COOH)
B:在pH=8的NaF溶液中,c(Na+)-c(F-)=9.9×10-7mol/L
C:pH=2的盐酸与pH=12的Ba(OH)2溶液等体积混合后,溶液中一定有C(H+)=C(OH-)
D:向0.1 mol/L氨水中加入少量NH4Cl固体,溶液中c(OH-)/c(NH3.H2O)增大
缺乏维生素,人体的正常生长发育将会受到影响,甚至引发疾病.下列说法正确的是( )
根据短文内容判断下列说法的正误。
There are four seasons in a year.They are spring,summer,autumn and winter.Spring is green with flowers.I can plant trees in spring.Summer is hot.I can swim in the sea.In autumn,farmers are busy.I can eat moon cakes and pick apples in autumn.But I like winter best.Winter is cold.Sometimes it snows.I often skate in winter.Sometimes l make a snowman.
x,y是两个不为0的自然数,如果x× 67 =y÷ 76 ,那么( )。