Astronomers study the expansion of the universe, contemplating processes that unfold over an eternity of cosmic time.
天文学家研究宇宙的膨胀，思考在宇宙时间的永恒中展开的过程。
Which choice best defines “eternity”?
A — Time without end. “eternity” means time without end.
Which word means “time without end”?
B — eternity. “eternity” means time without end.
eternity — time without end. In Chinese: 永恒.
eternity is pronounced /ɪˈtɜːrnəti/.
Astronomers study the expansion of the universe, contemplating processes that unfold over an eternity of cosmic time. (天文学家研究宇宙的膨胀，思考在宇宙时间的永恒中展开的过程。)
forever, perpetuity, infinity — all close in meaning to eternity (time without end).
moment, instant — each the opposite of eternity (time without end).
Yes. eternity is on the SAT Prep Basic list — the everyday academic words the SAT assumes you already have. The Digital SAT does not test vocabulary in isolation; words like this one are tested through Words in Context questions, where you choose the word that completes a passage most logically and precisely.