—It's a townhouse.
A:How is your house like?
B:Where's your house?
C:What kind of house do you live in?
D:How do you like your home?
如果你想知道Bill在周末必须做什么,你这样问他:
____ do you ____ ____do on weekends?
空气是一种宝贵的自然资源。空气中含量最多的两种气体是( )
明矾石的主要成分是K2SO4•Al2(SO4)3•2Al2O3•6H2O,还含有少量Fe2O3杂质.利用明矾石制备氢氧化铝的流程如下: