Answer:
mucus
trachea
<em><u>hope</u></em><em><u> it</u></em><em><u> helps</u></em><em><u> you</u></em><em><u> </u></em><em><u><</u></em><em><u>3</u></em>
Ecosystems experience change through human activity and natural events. This is because human activity can impact changes in nature, like climate for example. As a result, ecosystems change in response to the change in nature or natural events, which was caused by human activities. They are interrelated so to speak.
It made me feel sad but also happy that they didn’t chose
C. Evidence of ancient tropical swaps in cold regions of North America
The answer is b gamete formation.