Who conducted the first experiment showing that plants change the composition of the air? john woodward jan ingenhousz jan van helmont joseph priestly?

Plz ive been stuck on this question forever. in 1753 george washington was sent on a mission to a. build a fort at the point where the allegheny and monongahela rivers form the ohio river. b. attack the french at fort duquesne. c. attack the french at fort neccessity. d. deliver a message to the french demanding that they leave the ohio river.

Which of the following explains why scarcity is a basic fact of life a. demand will always be greater than supply b. technology has not advanced far enough yet c. there will always be too many people on earth d. people cannot make good allocation decisions

What is an example of a primary source? o a. a dictionary entry o b. a history book o c. an encyclopedia article o d. a recording of a speech