Which units is the standard unit (metric unit) for speed

Answer

Metric time is the measure of time intervals using the metric system. The modern SI system defines the second as the base unit of time, and forms multiples and submultiples with metric prefixes such as kilo seconds and milliseconds. Other units of time: minute, hour, and day, are accepted for use with SI, but are not part of it. Metric time is a measure of time intervals, while decimal time is a means of recording time of day.

Explanation:

no simpler subs form complex ones. synthesise = make

he made 11 calls in one day