True, is the correct answer.
I would think it is a heterogeneous mixture since it can't be an element since there are more than one type of atom, it can't be a compound since the leaves are not bonded together, and it can not be a homogeneous mixture since the leaves don't all blended together (the pile is not uniform) and you can distinguish all the different parts of the mixture. It can be considered a heterogeneous mixture since the leaves are mixed together (along with other things like dirt) in a non-uniform way so that you can point out the parts of the mixture and it does not look like one thing.
I hope this helps. Let me know in the comments if anything is unclear.
The correct answer is "B. Make a Hypothesis".
In which elements are belonging to? I will grant that option B ; ti's the best answer.
In which thou might contain the elements zinc , gold , aluminium , and last by not least oxygen.
I truly hope ti's answer helps thou.
Answer: Option (B) is the correct answer.
Explanation:
It is known that for writing a chemical reaction equation, reactants are written on left hand side whereas products are written on right hand side.
And in between reactants and products a forward arrow is placed pointing towards the products.
Therefore, the reaction for carbon burns in the presence of oxygen to give carbon dioxide will be written as follows.

Here, carbon and oxygen atoms are the reactants whereas carbon dioxide is the product.