麦克斯韦速率分布曲线是___Maxwell's rate distribution is___

A、两头小中间大的对称分布曲线；Symmetricaldistributioncurvewithsmallatbothendsandlargeatthemiddle;;
B、两头小中间大的不对称分布曲线；Anasymmetricaldistributioncurvewithsmallatbothendsandlargeatthemiddle;;
C、两头大中间小的对称分布曲线；Symmetricaldistributioncurvewithlargeendsandsmallmiddle;;
D、两头大中间小的不对称分布曲线；Anasymmetricaldistributioncurvewithlargeatbothendsandsmallinthemiddle;