Answer: Hot air is less dense than cool air; the heated air causes the balloon to rise simply because it is lighter than an equal volume of cold air. Buoyancy is an upward force that the air exerts, and it helps hot-air balloons and blimps stay in the air. A hot air balloon uses a burner to heat up the air inside the balloon.
Muslims still ruled Jerusalem but Christian pilgrims could still access the city for free.
Im for sure rivers and mountains.
You should post the choices so people can help
The Berlin Blockade (1948–49) was the first major crisis of the Cold War. With the victory of the Communist side in the Chinese Civil War and the outbreak of the Korean War (1950–53), the conflict expanded.
