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Control Group

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Placeble 228 x/6n⬜⬜⬜⬜⬜n⬜⬜⬜⬜⬜n⬜⬜⬜⬜⬜n⬜⬜⬜⬜⬜n⬜⬜⬜⬜⬜n⬜⬜⬜⬜⬜

The xkcd store is back, with shirts, stickers, and posters for sale.