Final answer:
An aircraft carburetor is equipped with a mixture control in order to prevent the mixture from becoming too rich at high altitudes.
Step-by-step explanation:
An aircraft carburetor is equipped with a mixture control in order to prevent the mixture from becoming too rich at high altitudes. At high altitudes, the air density decreases, and the carburetor compensates for this by adjusting the fuel-air mixture to prevent it from becoming too rich. This ensures the proper combustion and performance of the engine.