一 What's wrong with my eyes, doctor?
一 I'm afraid you have to wear glasses to help see things ______.
A:sadly
B:luckily
C:clearly
驱动水循环的能量主要是( )
①MnO2+H2O2+2H+=Mn2++O2↑+2H2O
②Mn2++H2O2=MnO2+2H+
下列说法正确的是( )
陆游在《老学庵笔记》中记载:宋代成都“席帽行范氏,自先世贫而未仕则卖白龙丸,一日得官,止不复卖;城北郭氏卖豉亦然,皆不肯为市井商贾或举货营利之事”。这种现象( )