A:一定是锐角三角形
B:一定是直角三角形
C:一定是钝角三角形
D:可能是锐角三角形,也可能是钝角三角形
In many places in China, the old over 90 ____ (take good care of) not only by their family but also by the government.
下列事例中,哪一个事例不能表明物体的分子在不停地做无规则的运动( )
--It is said that it was invented
将要成熟的大豆豆荚加工成的菜肴,俗称“毛豆”.在栽培过程中因某种因素引起花粉发育不良,影响传粉受精,如果要保证产量,可采用的补救方法是( )