Answer:
An eon
Explanation:
The first broad division of the geologic timescale is the eon. Others are Eras, Periods and Epoch.
Eons are the most broad and the largest of divisions of the timescale. There are two categories of the eons which are:
- Hadean eon
- Archean eon
- Proterozoic eon
- Phanerozoic eon
The Phanerozoic eon is the most recent. The Hadean eon is the is the oldest eon.
Dark matter makes up about 27% of the universe.
The last statement is the correct answer. However, the second question is theoretically historically correct, for Иосиф Сталин (Joseph Stalin) practically controlled the entire government of the USSR with his oppressive ultra-authoritarian non-democratic Stalinist-"Communist" regime.