Right before the big algebra test, the dinosaur felt like he was a <u>nervous rex</u> (nervous wreck, get it?).
This showcases a play of words in the Punchline Algebra book, wherein the answers somewhat rhyme with the correct word that describes the situation.
Pretty sure it was new disease, since Columbus brought small pox, measles, and the influenza with him to America. Hope this helps!

Manchuria rich in natural resources and sparsely populated had obvious advantages for a densely populated and resource-poor Japan. Amongst Manchuria's resources coveted by Japan were iron, coking coal, soybeans, salt and above all land, all severely lacking within the Japanese empire in 1930.