thE prEvAiling winD is thE winD DirECtion most oFtEn oBsErvED During A givEn timE pErioD. winD spEED is thE rAtE At whiCh thE Air movEs pAst A stAtionAry oBjECt.
A．motionlEss
B．mAssivE
C．FlExiBlE
D．notiCEABlE