What was the cause of workers dying at St. Petersburg construction sites ?

Compare demographic and environmental effects of the columbian

Which statement explains what upwelling causes? a. upwelling causes tides to rise and fall. b. upwelling causes changes in the direction of currents. c. upwelling causes nutrients, minerals, and tiny organisms to rise. d. upwelling causes currents in the pacific ocean to change direction. i think the answer is c.

The climate in the temperate zone is cold in summers and warm in winters very cold year-round very warm year-round warm in summers and cold in winters