Answer:
D. in the past few decades, carbon dioxide levels have been falling.
Answer:
Yes, it actually is!
Explanation:
Your backyard is a great example of an ecosystem. You may have a lawn, which sprouts mushrooms, is home to squirrels and birds, and other forms of life.
Answer:
B. the way they are formed
Explanation:
Black for the first,
Brown for the second,
And,
White for the third.
Hope that his helps you..
A group of tissue that work together is a organ