Answer:
A <u>subordinate clause</u> is a group of words containing a subject and a predicate but is not a sentence on its own.
Explanation:
Ex:
<u>after </u><u>I ate</u><u> lunch</u>
<u>because</u><u> I am</u><u> short</u>
What are you trying to say
As Earth cooled, an atmosphere formed mainly from gases spewed from volcanoes. It included hydrogen sulfide, methane, and ten to 200 times as much carbon dioxide as today's atmosphere.
