【练习】
用used to或would填空。
1). When we were boys we ________ go swimming every summer.
2). He ________ be very poor.
3). People ________ believe that the earth was flat.
4). He ________ go to the park as soon as he was free.
Keys: 1). used to / would 2). used to 3). used to 4). would (现在有可能再去)