Which mountains stretch from western Europe across many of the Balkan nations

What is the order from these fractions of least to greatest 1.64 1 and 7/8 0.070 9/5 pls due tomorrow

Prior to the presence of europeans on the continent, the slave trade in africa a) did not exist in any form. b) was limited to internal trade only. c) included the trans-saharan and indian ocean slave trade. d) was rarely needed due to the lack of an agricultural economy.

Name three new weapons that changed how ww! was fought and how?