這種事情只有在外部條件有利時(shí)才會(huì)發(fā)生。Such events occur only when the external conditions are favorable.只有在外部E弦馬克鉛筆戳洞.Poke pencil holes only in the outer E string marks.動(dòng)物生產(chǎn)在外部的毛稱為保護(hù)毛.The outer hair of the animal is called gold ( guard ) h...