user: You are a structured reasoning expert tasked with solving problems step by step. 
You first think about the reasoning process in the mind and then provide the answer. The reasoning process and answer should be enclosed within <think> </think> and <answer> </answer> tags, respectively, i.e., <think> reasoning process here </think> <answer> answer here </answer>. 
Given a question and the associated knowledge graph triplets (entity, relation, entity), you are asked to answer the question with these triplets and your own knowledge. 
You can break down the original question into several sub-questions and explore the given knowledge graph to solve them step-by-step. If there are multiple possible answers, choose one as the final answer. 
After thinking, when you finally reach a conclusion, clearly state the answer within <answer> </answer> tags, i.e., <answer> answer here </answer>. 
Question: centimetre–gram–second system of units is the unit of acceleration of what measurement system? 
Knowledge Triplets: Centimeter, measurement_unit.distance_unit.measurement_system, Centimetre–gram–second system of units
Centimetre–gram–second system of units, measurement_unit.measurement_system.luminance_units, Stilb
Centimetre–gram–second system of units, user.movgp0.default_domain.measurement_system.base_units, Centimeter
Centimetre–gram–second system of units, measurement_unit.measurement_system.magnetic_flux_density_units, Gauss
Statcoulomb, measurement_unit.charge_unit.measurement_system, Centimetre–gram–second system of units
Centimetre–gram–second system of units, user.movgp0.default_domain.measurement_system.base_units, Second
Centimetre–gram–second system of units, measurement_unit.measurement_system.length_units, Centimeter
Oersted, measurement_unit.magnetic_field_strength_unit.measurement_system, Centimetre–gram–second system of units
Centimetre–gram–second system of units, measurement_unit.measurement_system.energy_units, Erg
International System of Units, measurement_unit.measurement_system.time_units, Second
Gal, measurement_unit.acceleration_unit.measurement_system, Centimetre–gram–second system of units
Gal, measurement_unit.acceleration_unit.acceleration_in_meters_per_second_squared, 0.01
Centimetre–gram–second system of units, user.movgp0.default_domain.measurement_system.base_units, Gram
Centimetre–gram–second system of units, user.movgp0.default_domain.measurement_system.base_units, Kelvin
Centimetre–gram–second system of units, user.movgp0.default_domain.measurement_system.unit_of_time, Second
Centimetre–gram–second system of units, base.schemastaging.context_name.pronunciation, g.125_mqyp3
Abcoulomb, measurement_unit.charge_unit.measurement_system, Centimetre–gram–second system of units
Centimetre per second, measurement_unit.speed_unit.measurement_system, Centimetre–gram–second system of units
International System of Units, measurement_unit.measurement_system.length_units, Centimeter
Centimetre–gram–second system of units, measurement_unit.measurement_system.density_units, Gram per cubic centimetre
cgs.noun.01, base.wordnet.synset.equivalent_topic, Centimetre–gram–second system of units
Centimetre–gram–second system of units, measurement_unit.measurement_system.acceleration_units, Gal
Centimetre–gram–second system of units, user.movgp0.default_domain.measurement_system.unit_of_lenght, Centimeter
Gram per cubic centimetre, measurement_unit.unit_of_density.measurement_system, Centimetre–gram–second system of units
Abampere, measurement_unit.current_unit.measurement_system, Centimetre–gram–second system of units
Centimetre–gram–second system of units, user.movgp0.default_domain.measurement_system.unit_of_temperature, Kelvin
Gram, measurement_unit.mass_unit.measurement_system, International System of Units
Barye, measurement_unit.pressure_unit.measurement_system, Centimetre–gram–second system of units
Centimetre–gram–second system of units, user.movgp0.default_domain.measurement_system.unit_of_mass, Gram
Stilb, measurement_unit.luminance_unit.measurement_system, Centimetre–gram–second system of units
Centimetre–gram–second system of units, measurement_unit.measurement_system.current_units, Abampere
Centimeter, measurement_unit.distance_unit.measurement_system, International System of Units
Centimetre–gram–second system of units, measurement_unit.measurement_system.magnetic_field_strength_units, Oersted
Gauss, measurement_unit.magnetic_flux_density_unit.measurement_system, Centimetre–gram–second system of units
International System of Units, measurement_unit.measurement_system.temperature_units, Kelvin
Centimeter, measurement_unit.distance_unit.measurement_system, Gravitational metric system
Centimetre–gram–second system of units, measurement_unit.measurement_system.charge_units, Abcoulomb
Centimetre–gram–second system of units, measurement_unit.measurement_system.charge_units, Statcoulomb
Centimetre–gram–second system of units, measurement_unit.measurement_system.speed_units, Centimetre per second
m.0h7jk8x, dataworld.gardening_hint.last_referenced_by, Centimetre–gram–second system of units
Erg, measurement_unit.energy_unit.measurement_system, Centimetre–gram–second system of units
Gravitational metric system, measurement_unit.measurement_system.length_units, Centimeter
Centimetre–gram–second system of units, measurement_unit.measurement_system.pressure_units, Barye

Answer: Gal