that are tigers,为什么不用this,those,tiger不是复数嘛,为什么不用those?

that are tigers,为什么不用this,those,tiger不是复数嘛,为什么不用those? This is a boy and those are girls.这个句子中为什么用those不用that呢? These cups are ours. Those are others.为什么不用others' 比较级后面的代词为什么用that/those而不用it/one? nobody but doctors or nurses and those invited为什么不用are invit 为什么常用those作为先行词,而不用其他代词 在这里为什么用those而不用them? 为什么suggestion不用复数? we know that tigers eat meat tiger为什么加S those are tiger cubs.改一般疑问句 God helps those who help themselves(为什么用help,不用helps)?再告诉下定语 Is there any tea in those cups?为什么不用Ara there any tea in tho