—
A:Yes, he is.
B:Yes, he did.
C:No, he doesn't.
根据句子意思,从下列短语中选择恰当的填入空格中。
be occupied with keep it up fit in take in cast down in favor of in vain
已知△ABC中,D、E分别是AB、AC的中点,则S△ADE:S△ABC= ____
先化简,再求值:(2a+b)(﹣b+2a)﹣(2a﹣3b)2﹣5b(3a﹣2b),其中a=﹣ 12 ,b= 13 .
儒家思想逐渐成为中国封建社会正统思想,始于( )