n.效用,利益;
vt.& vi.有益于,有益于;使对某人有利;
例句:
Now that you have the chance, you have better avail your self of it.
你既然有这个机会, 最好利用它.
Saw time running out, also to avail and around, I can not help burning.
眼见时间一分一秒地流逝, 还在徒劳无功地转悠, 我不禁心急如焚.
So the guard watched him ever more closely, but to no avail.
所以警卫更加小心地盯紧他, 但是这样做完全于事无补.