The following sentences form a paragraph. The first and fourth sentences of the paragraph are given. The rest are numbered as P, Q, R, S and T. These five parts are not given in their proper order. Arrange them in the correct order to make the paragraph meaningful and then answer the questions given below.

1. Alaska's national parks offer a unique opportunity to explore glacial environments.

P. The part that once connected the two land masses is now underwater, beneath the Bering Strait. 

Q. It used to connect East Asia and North America. 

4. This bridge was the primary pathway used by the original colonists of the Americas some 15,000 to 20,000 years ago.

R. And hence the name ‘Bering Land Bridge’.

S. They are nestled in a wilderness so wild you'll need to arrange for a boat or a plane to get there. 

T. The Bering Land Bridge National Preserve, located in northwestern Alaska, near Nome, is one of the most popular of these parks.