Two years ago she bought an expensive mountain bike and then she persuaded me to buy .A.

问题补充：

Two years ago, she bought an expensive mountain bike and then she persuaded me to buy .

A. this

B. that

C. it

D. one

答案：

A. this

B. that

C. it

(答案→)D. one

解析：句意：两年前她买了一辆昂贵的山地车，现在她说服我也买一个。这里需要一个代词指代an expensive mountain bike，可以用one泛指前面的可数名词，this“这个”表示近指，that特指可数名词的单数或不可数名词，it是指同类同物，所以选D。