Question: I just read about using cardboard in layers for building, but the surfaces should be waxed to keep out water.  This premise is used by some _____________ to keep water in:
Choices:
text: balloons
label: A
text: plastic bottles
label: B
text: leaves
label: C
text: books
label: D
Answer: C
Fact: waxy leaves are used for storing water by some plants