A:铝比锌的金属活泼性更弱
B:相等质量的铝和锌和足量稀硫酸反应,铝产生的氢气多
C:锌原子的最外层电子数比铝多17
D:铝的相对原子质量为26.98%
—As we know, planting trees is good for the environment. _______ will we plant trees on the hill?
—Maybe in two weeks.
方程组x+y=12x+y=6的解的个数为( )