下列各组液体混合物，用分液漏斗不能分离的是( )A.溴乙烷和水 B.氯乙烷和稀盐酸C.甲苯和水
—You seemed toke deeply struck by his skill. —Not exactly so. It was his courage _____ his skill that really struck me mast. A. rather than B. as well as C. but also
某科学家估测一个密度约为kg/m3的液态星球是否存在，他的主要根据之一就是它自转的周期，假若它存在，其自转周期的最小值约为（）（万有引力恒量
谚语“苏湖熟、天下足”，反咉了中国南方经济发展水平超过北方的史实。这一现象最早发生在（ ）A．汉朝B．隋朝C．唐朝D．南宋
下图中能反映我国农业技术史上农用动力的一次革命的是（ ）
In the hit film The bucket List, Jack Nicholson and Morgan Freeman meet in hospital in California after they have been diagnosed with cancer. Between them they cook up a “bucket list” – a to-d
如图所示，某同学用插针法测定一半圆形玻璃砖的折射率．在平铺的白纸上垂直纸面插大头针P1、P2确定入射光线，并让入射光线过圆心O，在玻璃砖（图
已知A=B=R,x∈A,y∈B,f:x→y=ax+b,若5和20的原象分别是5和10,则7在f下的象f(7)=.
截圆
得的劣弧所对的圆心角是 （ ）
B．
C．
D．
