A:had been made
B:was made
C:has been made
D:would be made
2014年诺贝尔物理学奖由蓝光二极管的发明者获得,这项发明使制成白光LED灯成为现实.要制成白光LED灯,除蓝光二极管外,还需____ 、____ 两种色光二极管.