What is roosevelt’s claim about the role our forbearers in conservation?

“Conservation as a National Duty" was a speech given by Theodore Roosevelt in 1908 in front of many members of parliament. Roosevelt states that the forefathers of America wouldn't have known how much of an impact their actions would have on future generations. In general Roosevelt states that throughout history previous historic figures had no idea if their ideas would be successful and if they would help with conversation or not.

hm, switch the relative; nominative and indefinite; objective ? not too bright in the knowledge of the english.

the rigid outer part of the earth, consisting of the crust and upper mantle is the lithosphere.     answer   crust and outer part of the mantle.