Easyme! which of these surface features are formed when the acid in groundwater reacts with limestone?
a. rivers and springs
b. sinkholes and caves
c. hotsprings and geysers
d. wetlands and volcanoes

With i really need the correct answer!

Which type of bond is found between the atoms of a molecule? a. metallic b. delocalized electron c. covalent d. ionic

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)