Difficulties and hardships have ________ the best character of the young geologist.
It was a pity that the great writer died _______his works unfinished.
The boys were happily making a snowman, _________ with cold.
________ the prices and functions of different types of computers before you make up your mind which to buy.
-- Are you fond of watching TV? --- Not a bit. I would sit alone in the dark _______ I would watch TV.
--- Does Li Hua serve in the army? ---No, but he________ in the army for three years.