I read three books on this subject, no one of which was helpful.
关于这个课题我读过三本书，可没有一本是有用的。
Tip: It's very helpful to set up three piles: keep, re-locate, and toss.
提示：把东西分成三类会有帮助：保留、另放和丢弃。
This is the most helpful (useful) book of the three.
这是三本中最有用的书。
This is the most helpful (useful) book of the three.
这是三本中最有用的书。
应用推荐