Bruce ________ at 6:15 in the morning.
A: brush his teeth
B: brushes his teeth
C: brush his tooth
D: brushes his tooth
选词填空。
奢望 奢侈
①刘翔刚练跨栏时,不敢____能亲眼看到约翰逊。②他的生活非常____。
根据质量守恒定律:2AB+B2=2C中,C的化学式是( )