A.18% B.19% C.20% D.21%
A.34.18% B.36.23% C.38.46% D.41.27%
A.創(chuàng)造發(fā)明成本 B.法律保護(hù)成本 C.發(fā)行推廣成本 D.轉(zhuǎn)讓機(jī)會(huì)成本