8．________ adj. of great value and beauty 9．________ adj. full of strong desire 10．________ adj. taking place by degrees 11．________ v. make or become larger 12．________ adj. clearly seen or understood 13．________ n. state of being warm 14．___________ n. major achievement，eg. in technology 15．________ adj. changeable；not reliable

precious

eager

gradual

expand

apparent

warmth

breakthrough

uncertain