Erie has 100 000 people, and Pittsburgh has 300 000 - so from the first two Pittsburgh is the bigger one.
Philadelphia has 1.5 million people living in it - it is also the biggest city in Pennsylvania (this is the state where all the cities are) - and this is also the correct answer!
It is not the capital however, as it's Harrisburg.
Northern european according to atlas ... but im not sure ... so I dnt want your to get it wrong... go w your best instinct
Global climate change is when a change in weather appears in an area where it normally wouldn't. This is normally a change in the temperature, precipitation and/or wind. An example would be the ice caps melting in Antarctica because heat is making its way in where it should not be.
The mantle is actually a liquid. The intense heat of the core of the Earth causes the mantle to move in convection currents.
