Because early Earth lacked oxygen in its atmosphere, it also lacked a protective ozone barrier.

因为早期的地球大气中缺乏氧气，所以也缺乏起保护作用的臭氧层屏障。

youdao

Reporters also raised hard questions about sloppy housekeeping, claiming, for example, that the Kursk lacked the right emergency batteries, food and oxygen supplies.

ECONOMIST: The damage done