Is the more densely population european annationst

The most densely populated European nation is the Vatican, located within Rome. It has 800 citizens with them living on a 0.17 miles squared, meaning there are 4,709 citizens per mile squared. This number might seem odd since it's much greater, but as Vatican is smaller than 1 mile, it cannot be compared without it becoming so big.

Sonar is an application of the doppler effect used by submarines.  this test was on k12.

Forms from the water cycle