举例说明1，Yesterday i bought a new bike . it is blue.(it指前文刚提到的名词单数）2.I have many friends . They are all young.(they前文刚提到的名词复数）3.A bridge made of stone is stronger than one made of wood（one是单数与前文不定冠词对应4. The bridge made of stone is stronger than that made of wood.（that=the one 表示特指与前文定冠词the对应）5.The people who are standing ...
