A.累計(jì)接觸粉塵時(shí)間越短,越容易引發(fā)塵肺病 B.累計(jì)接觸粉塵時(shí)間越長(zhǎng),越容易引發(fā)塵肺病 C.與累計(jì)接觸時(shí)間無(wú)關(guān)長(zhǎng)短無(wú)關(guān)
A.就近原則 B.先近后遠(yuǎn) C.先易后難
A.3 B.4 C.2