Fahrenheit is a customary unit
Use whatever is common in your country. In the long term, however, the entire world should switch to metric, for reasons of standardization, so if you happen to live in a country that uses non-metric units, you might try to push for metrification.
Oh Dear!!!! your English grammar is at fault. The question should read ' Which metric unit is the mass of an orange?'. NB 'Witch' is a female sorceress 'Which' is the question. To answer the question, an orange would be weighed in grams.
The basic metric unit for length is the metre. Rivers would be measure in kilometres (1,000s of metres)
Metric. Pro-tip: If you can add mili- centi- deci- to the front... its metric. ++++ Not sure that's much of a tip. The prefixes are simply divisions, but it is true that they are used normally only for metric units. However, the litre is indeed part of the metric system: it is the basic unit of fluid volume.
No - a yard is a unit in the imperial system - its metric equivalent is 0.9144 metres.
It is a customary unit.
customary
A "gran" is a German measurement, it is neither customary or metric. A "gram" is a metric unit.
Metric.
The pound is NOT a metric unit.
It is a customary unit.
customary
I'm guessing by customary, you mean imperial. if so inches are customary/imperial
it is a customary unit
It is the basic unit of time in both systems.
The customary unit would be miles (mi), and the metric unit would be kilometers (km).
The yard is an English, or customary unit.