Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to understand the metric system [title] Memorize the base units. [step] Unlike the imperial system, which uses many different units for the same quantity, the metric system uses a single base unit for each type of measurement. Each base unit is unique to that particular type of measurement.

Ending1: Try to learn about the base units by studying their bases. [substeps] The base units are present the same number of units. Ending2: [title] Determine what measurement system you need to compute. [step] Metric system is standardized in a technical manner based on the measurement system. Ending3: [substeps] The base unit for measuring volume is the liter (l). The base unit for measuring length or distance is the meter (m). Ending4: If the base unit uses a specialized unit for a unit of measurement, it has minimal registration in that unit. These bases usually rely on the unit's atomic composition and percentage of the atomic.

Answer format: ending1/ending2/ending3/ending4