pointless

参与毫无意义的争论只会浪费时间和精力。

Engaging in ___pointless arguments only wastes time and energy.

没有明确的目标，这个项目感觉像是徒劳无功的操练。

Without clear goals, this project feels like a ___pointless exercise.

她意识到向无响应的地址发送电子邮件是毫无意义的。

She realized that sending emails to an unresponsive address was ___pointless.