非金属氧化物采用不同的分类方法可分为不同的类别,从某种意义将N2O5、SO3、CO2、Cl2O7等归为一类。则下列氧化物与它们属于同一类的是( )
His sister left home in 1998, and _______since.
What do you mean, there are only ten tickets? There _____ be twelve
Could I speak to ______ is in charge of International Sales please?
How much _______ she looked without her glasses!
Let’s go to ______ cinema – that’ll take your mind off the problem for _____while.