选择方框内的单词完成下列句子， 使句子通顺、正确。
A. knowledge B. twentieth C. largest D. written E. hungry F uncomfortable.Bruce is _______ , so he can’t go to school today .
He lives on the _______ floor . He uses a lift to go up and down.
China has the _______ population in the world .
The books _______ by Mr White are very interesting .
I’m not _______ , but I’m a little thirsty .
Our _______ of the universe is growing all the time .