Available options:
i. layers of fat;
ii. electricity;
iii. food;
iv. focusing a lens;
v. shadows;
vi. dolphins;
vii. Light bulbs;
viii. pets;
Q: Fact 1: Alight bulb is used for seeing in the dark. Fact 2: Humans are unable to see clearly in the dark. Given the two facts above, what helps humans see?
A:
vii.