Are there enough people on hand to hold a meeting?
(on hand means available)
Employee absenteeism has gotten out of hand.
(out of hand means out of control)
（out of hand指无法控制）
Could you lend me a hand with this piano?
(lend someone a hand means help)
（lend someone a hand指帮助）
Tom was hands-down the best student at the University.
(hands-down means obviously)
The exams at two. Will you keep your fingers crossed for me?
(keep your fingers crossed means wish for good luck)
（keep your fingers crossed指祈祷好运）