n.效用,利益
vt.& vi.有益于,有益于,使对某人有利
I apologized repeatedly, but to little avail.
我一再道歉,但丝毫没有奏效。
His efforts were to no avail.
他徒劳无功。
We tried to keep him alive but to no avail.
我们全力抢救他,但却徒劳无功.