Three years ago,Cathy---(更喜欢)reading English novels.

问题描述:

Three years ago,Cathy---(更喜欢)reading English novels.

Three years ago,Cathy preferred (更喜欢)reading English novels.

prefer doing sth. 更喜欢做某事.【这里需要一般过去时,preferred 】
prefer to do sth. (意思同上)

prefer doing sth. to doing sth. else(更喜欢做某事而不是做别的事.)