He knew it was useless to protest.
他知道抗议是徒劳的.。
I was conned into buying a useless car.
我上当受骗买了辆不能用的汽车。
I'm useless at French.
我的法语不太行。
It is useless to speculate why he did it.
对他为什么这么做妄加猜测毫无用处。
The measures were decried as useless.
这些措施受到指责，说是不起作用。
