【英语问题】Mr Brown was very tired yesterday,because he kept______（wal_英语解答

【英语问题】Mr Brown was very tired yesterday,because he kept______（walk）for two hours.
横线处为什么填“walking",而不是"to walk"

人气：208 ℃　时间：2020-02-04 05:35:34

解答

keep doing sth 一直做某事
连续走了两个小时,中间没有停