A true friend is invaluable and precious.
一个真正的朋友是无价和珍贵的。 (Yī gè zhēnzhèng de péngyǒu shì wújià hé zhēnguì de.)
"I've known her for years, and she's always been there for me; a friend is a treasure."
"我认识她好多年了，她一直都在我身边；朋友就是宝藏。" (Wǒ rènshi tā hǎoduō niánle, tā yīzhí dōu zài wǒ shēnbiān; **péngyǒu jiùshì bǎocáng**.)
an unidentified but informed source
To keep something secret.
to trust someone even when you are not sure they are honest
a simple and perfect solution to a complex problem
to secure something so it cannot change
plans are uncertain or not decided yet
