Weareobligedtothembecausesomeoftheselanguageshavesincevanished,asthepeopleswhospokethemdiedoutorbecameassimilatedandlosttheirnativelanguages.
正确答案:我们之所有感激他们(两位先驱),是因为在此之后,这些(土著)语言中有一些已经不复存在了,这是由于说这些语言的部族或是消亡了,或是被同化而丧失了自己的本族语言。

Weareobligedtothembecausesomeoftheselanguageshavesincevanished,asthepeopleswhospokethemdiedoutorbecameassimilatedandlosttheirnativelanguages.
正确答案: