正确的化学方程式是（ ）
A：CaO+H2O→Ca（OH）2
B：2H2O→2H2↑+O2↑
C：4Fe+3O22Fe2O3
D：Zn+HCl→ZnCl2+H2↑
下面对子女孝敬父母的行为理解正确的是（ ）
Lucy was born ______ January 30th, 1998, when her sister got married ______ a fashion designer.
5－3＝____ 50－30＝____500﹣300＝____
231＋150＝____281＋100＝____131＋250＝____
It ______ him an hour to play basketball every day.
