4 The line segment on the map below is 1.6 cm long, and the map scale is 1 cm = 0.5 km. What is the gradient of the slope marked by the line? A. 600 m/km
B. 1,333 m/km
C. 750 m/km
D 500 m/km

The lines marked by the letters a, b, and c on the map above represent a. chains of volcanoes b. earthquake fault lines c. thin strips of heavy forests d. major rivers that flow from north to south

Which are evidence of the seafloor spreading? a. molten material b. magnetic stripes c. continental material d. drilled core samples e. ocean water samples

Fertility and mortality rates are higher in more developed nations.