Translator: Andrea McDonough Reviewer: Morton Bast

I'm a mechanical engineering professor

at the University of Pennsylvania,

and my favorite hobby is photography.

And as I travel around the world,

I l

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Translator: Gisela Giardino Reviewer: Sebastian Betti

Here's a piece of paper.

I will fold it and cut it, like this.

And now with these two pieces I will do the same.

Now I'll put it all together and

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