a. 引不起兴趣的, 无趣味的, 乏味的

boring/bored/tiring/tired/dull/uninteresting
记忆：
1. boring [ 5bC:riN ] adj. 令人厌烦的 The film was so boring that we left the cinema twenty minutes later. 电影很无聊。我们二十分钟后就离开了电影院。
2. bored adj. 无聊的 The bored boy borrowed a book and soon found it boring. 感到无聊的男孩借了一本书，但很快又发觉书无聊。
3. tiring [ 5taiEiN] adj. 疲劳的, 累的 The work is too tiring. We have to take a break now and then. 工作太劳累了。我们不得不时不时休息一下。
4. tired [ 5taiEd ] adj. 引起疲劳的, 累人的 We are tired from our heavy lessons these days.这段时间我们作业太重，感到很累。 be tired of sth 讨厌 be tired from sth因……而疲倦
5. dull [ dQl] adj. 感觉或理解迟钝的, 无趣的 Tom is not a dull boy at all. He can think of wonderful ideas and amuse everyone except those trapped in his plans. 汤姆一点儿也不无聊。他能想出好主意让除了那些中他圈套的人外的人都开心。
6. uninteresting [ 5Qn5intristiN ] adj. 无趣的, 令人厌倦的 Well, to be honest, we think it is uninteresting. 好了，说实话，我们认为那没有味道。
另类阅读：
The tired students won’t listen to any boring talk. If the speech is dull, they will feel bored. Therefore, leave the uninteresting things out from your speech.