keep :保存（多久时间）How long can I keep the book?
保持（状态）:keep warm/silent/up/off/away等
维持（和平等）：keep peace
记,写(日志等)：keep diary
阻止,妨碍：keep sb from doing sth
继续做某事 keep doing sth
last:持续（多久时间）：The rainy days will last one week.
(时间)刚刚过去的：last week上周
（顺序）最后的 the last week