取一小物块轻轻放入盛满煤油的烧杯中,静止后溢出了8g煤油,将其轻轻放入盛满水的烧杯中,溢出了水的质量不可能是下列的(其中=1g/cm³,=0.8g/cm³)(    )

质量相同的实心木块、铝块、铜块同时放入足够深的水槽中静止时,三个物体所受浮力(    )

如图,完全浸没在水中的乒乓球,放手后,乒乓球从上浮到静止的整个过程中,其浮力大小变化情况是(    )

如图所示,质量相同的甲、乙、丙三个物体浸没在水中的浮沉情况,此时甲、乙、丙三个物体所受的浮力分别为、、,则下面关系正确的是(    )

如图,四边形ABCD,M为BC边的中点.若∠B=∠AMD=∠C=45°,AB=8,CD=9,则AD的长为()

如图,将含30°的三角板DEF(其中∠EDF=30°)的锐角顶点D与等腰△ABC(其中∠ABC=120°)的底边中点O重合,两边分别与线段AB,BC相交于点P,Q.若AC=,AP=,则BQ的长为()

如图,M为线段AB的中点,AE与BD交于点C,∠DME=∠A=∠B=α,且DM交AC于点F,ME交BC于点G.(1)下列三对三角形:①△AMF与△BGM;②△DMG与△BDM;③△MEF与△AEM;其中相似的有         ;(2)连接FG,若α=45°,AF=3,CF=1,则FG的值为()

—How amazing the Great Wall is!—Yes, but it is very ____ to climb it.(tire)

“We must keep ____ in the library,”the librarian said to me____. (quiet)

—The accident was really terrible,wasn’t it?—Yes,it was.The young man on the bicycle was too ____.(care)