9.If you've ever seen that old optical illusion of a checkerboard and shadow, this is exactly the type of thing you can actively train your brain to get better at identifying, mostly just through practice.
10.As the long stretches of land were cleared or prepared for the plow, they were laid out like checkerboards into squares of forty, eighty, one hundred sixty, or more acres, each the seat of a homestead.
11.Instead, the pressure arranged the helium and sodium into a kind of 3-D checkerboard pattern, forcing pairs of electrons to separate and basically hang out on their own in between the helium atoms, almost like a negatively charged ion without a nucleus.