The farmers _____ on the farm when suddenly a strange voice was heard.
A:were working
B:worked
C:are working
D:work
对下列生物或结构进行化学成分分析,最相似的是( )
David: ()
Kate: Nice to meet you, too.
《望岳》一诗中虚实结合的诗句: ____ ,____ 。
You can’t be late for school.(改为否定祈使句)
____ late for school.
(I)求f(x)的最小值;
(Ⅱ)在△ABC中,角A、B、C的对边分别是a、b、c,若f( C2 )=2且ab=c2,求A.