1. useless, powerless, complaining, sick, weak, conservative, rigid, helpless, unproductive, wrinkled, ugly, unattractive, and on and on.
    无用，无能，爱抱怨，多病，体弱，保守，僵化，无助，成不了事，满脸皱纹，丑陋不堪，魅力无存，等等，等等。

2. A car is useless without petrol.
    汽车没有汽油就不能使用.

3. It is useless to argue with the mind in this condition.
    在这种情况下，你又和头脑争吵让它松手是无济于事的。

4. I say judgment. Knowledge, no matter how broad, is useless until it is applied.
    我说是判断力。不管知识面有多宽，如果得不到应用，那就毫无用处。