Keep a pad handy to jot down queries as they occur.手边放一本便笺簿，以便有问题时随时记下。To make it easier to contact us, keep this card handy.把这张卡放在手边，以便于和我们联系。That key will come in handy if you lock yourself out.要是你把自己锁在了屋外，那把钥匙就派上用场了。...
42试金石试金, 黄金试人.42 As the touchstone tries gold, so gold tries man.试金之石可试金, 正如黄金能试人.As the touchstone tries gold, so gold tries man.这是试金法中用来测量样品金、银含量的传统方法.This is the traditional method used in assaying the content of gold...