Unefficient
無效的, 效率不高的
??? 情景例句
And how old are you?
你幾歲了？
It was a terrible experience,and I won't forget it.
它是可怕的經驗，我不會忘記它。
and at the most critical juncture we took turns in watching that point.
在最緊急的時刻，我們輪流監視那段河流的險情。