The synthetic air that humans will breathe on Mars will slowly become contaminated with carbon dioxide.
(The synthetic air; will breathe; L:on Mars) (The synthetic air that humans will breathe on Mars; will slowly become; contaminated with carbon dioxide) (The synthetic air that humans will breathe on Mars; contaminated; with carbon dioxide)
The synthetic air The synthetic air that humans will breathe on Mars The synthetic air that humans will breathe on Mars
will breathe will slowly become contaminated
L:on Mars
contaminated with carbon dioxide
with carbon dioxide