△ABC与△A′B′C′是位似图形,且△ABC与△A′B′C′的位似比是1:2,已知△ABC的面积是2,则△A′B′C′的面积是( )
____ ____ ____ ____his historic flight he became an international hero and legend.
处理工厂的废水。如硫酸厂废水中含有硫酸等杂质,可以用____ 、____ 等碱性物质中和。