A.社會(huì)福利問(wèn)題 B.公共物品問(wèn)題 C.市場(chǎng)失靈問(wèn)題 D.以上都是
A.電力B.水稻C.鐵路D.飛機(jī)
A.價(jià)格升高2%會(huì)導(dǎo)致需求量減少2% B.價(jià)格升高2%會(huì)導(dǎo)致需求量減少小于2% C.價(jià)格升高2%會(huì)導(dǎo)致需求量減少大于2% D.價(jià)格升高2%會(huì)導(dǎo)致需求量增加小于2%