The metre, second, and kilogram are SI base units.

### Why this is right The statement is true. The metre is the base unit for length, the second is the base unit for time, and the kilogram is the base unit for mass. ### The concept Base units are the standards assigned to fundamental quantities. They are distinct from derived units, which are constructed from base units. For example, speed can be expressed in metres per second, combining the length and time units. ### Terms - **International System of Units (SI)**: the shared scientific measurement system. - **Metre (m)**: the base unit of length. - **Second (s)**: the base unit of time. - **Kilogram (kg)**: the base unit of mass. - **Derived unit**: a unit made by combining base units. ### Remember Metre, second, and kilogram correspond to length, time, and mass.