Illuminance of illuminating radiation is always measured in photometric units.照明辐射的照度通常是以光度为单位.It refers to the specified average illuminance value on the lighted surface.规定的被照明表面上的照度平均值.Over a surface , Illuminance aver...
'Abracadabra,'said the conjuror as he pulled the rabbit from the hat.魔术师囗中念念有词, 把兔子从礼帽中掏了出来.Here is the magician and he says: Hey abracadabra, zero go away.女士们,先生们,这位是魔术师,他说 嘿, 零,走开.Where be out of order is abr...