a.  无用的；徒劳的 ≠ worthwhile ≈ pointless 

• futility   n. 无谓

• a futile attempt/effort  徒劳之举

• While the efforts are certainly not futile, the results of such bans will likely only start to be seen by generations down the line, bettering the world for the future. 努力肯定不是徒劳的，即努力肯定管用

• My efforts to go back to sleep proved futile. 我努力想再次入睡，但怎么也睡不着。

•  Brown's article tells of the tragedy and futility of war.  布朗的文章讲述了战争的悲剧性和无谓性。

BrE /əˌbriːviˈeɪʃn/