Which statement from the passage best sums up the writer's main argument? A.
The Freedom Trail in Boston is one of America's first historic walking tours.
B.
The city has a rich, historic past, and is a treat for anyone who loves history.
C.
Boston officially became a city in 1822, which makes it one of the oldest cities in America.
D.
Boston welcomes all its visitors with open arms and will make you want to stay forever!

its A

Explanation:

The Freedom Trail is a unique collection of museums, churches, meeting a ship, and historic markers that tell the story of the American Revolution and beyond.All Freedom Trail tours led by 18th-century costumed guides are excellent for sites and learn the history they tell while walking through modern city streets.

the gas pressure p, gas volume v, and gas temperature t are given in the formula:   pv=nrt,

r is the gas constant, and n is the number of gas moles.

if the container is cooled and remains under atmospheric pressure, where r is a constant that does not change, the volume of the container remains the same, the conclusion is drawn that, with all other values ​​unchanged, the number of gas moles n, is decreases.

the right answer is a.