1.Christmas comes but once a year.
2.A friend in need is a friend indeed.
3.To count one's chickens before they are hatched.
1.圣诞一年只一度。
2.患难时的朋友才是真正的朋友（患难见真情）。
3.蛋未孵出先数鸡（过早乐观）。
Learn the following by heart:
1.but adv. 只有；仅仅，意思接近only，是比较文气的用法。如：
He is but a child.
他只是个孩子。
I saw him but a few minutes ago.
我只不过在几分钟前见过他。
2.in need (of...)穷困；需要。如：
We should always help those in need.
我们应当总是要帮助那些家境困难的人。
He was not in need of money.
他不需要钱。
3.hatch v.孵出；出壳。如：
Ten chicks hatched (out ) this morning.
今早有10只小鸡出壳了。
The eggs are about to hatch.
这些蛋就要孵化了。
