Question

"passengers in a high-flying jumbo jet feel their normal weight in flight, while passengers in the orbiting space shuttle do not. this is because passengers in the space shuttle are"

Answer 1

Jumbo jets fly high in the sky....agreed....but they are essentially inside the earth's atmosphere....and earth's gravity pulls them towards itself, causing them to feel their normal weight, during flight.

Space shuttles, fly higher than jumbo jets, and far away from the earth's surface, where there's no gravitational pull of the planet. So they feel weightless, in Zero Gravity.