Which type of blood vessel normally contains valves to keep the blood flowing in One Direction a) arteries
b) veins
c) capillaries ​

B) Viens

The veins have valves to keep the blood pumping out and not coming back in the heart.

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.