Which of these factors contributed most to US westward expansion in the second half of the nineteenth century?
A
improved overland trails
O B. development of more railroad systems
OC. peace treaties with American Indians
OD. discovery of gold in Alaska

Will have the greatest effect on human health. pollution in the a. troposphere b. stratosphere mesosphere d. thermosphere

Which best explains how wealthy residents of italian cities contributed to the renaissance? a) wealthy residents bought works of art, which supported artists. b) wealthy residents participated in religion, which supported the church c) wealthy residents participated in music, which supported the arts. d) wealthy residents bought classical books, which supported scholars.

Martin luther started the protestant movement when he split from the church in 1517. what area of europe was he from?   a.  england  b.  italy  c.  yugoslavia  d.  germany