young sCiEntists DEmAnD thAt in orDEr to sAtisFy humAn nEEDs ______.
A．Existing proDuCts BE improvED
B．morE ComplEx mAChinEs AnD ElECtroniC EquipmEnt BE DEsignED
C．wAys BE FounD to proDuCE BEttEr gooDs using FEwEr rAw mAtEriAls
D．Any nEw invEntion AnD innovAtion BE EnCourAgED in tEChnology