Complete the following sentence with a (compound) word derived f

Complete the following sentence with a (compound) word derived from the one(s) given in bracket.

Be careful with the antique vase; it is （ ）.(price)

根据前文it is，说明空格处应该填形容词的形式，price的形容词为priceless无价的，且符合句意。句意：小心这个古董花瓶，它是无价之宝。