In the US, your religion is primarily chosen for you at birth. I wouldn't say there's one most popular religion that teens "join" though.
Christianity followed by Islam, Buddhism, Wicca
Christianity, Judaism, Islam, Buddhist
Most people in the US who profess any religion profess to be Christians. There are many denominations of Christianity in the US.
One of the most popular exports in the US is machines and engines. Another of the most popular exports in the US is a variety of electronic equipment.
Califonia is the most popular state in the US
As of 2011, the most popular song in the US is probably Firework by Katy Perry.
The most popular spice in the us is the peper.
Most people who live in the US believe in Christ
they are the most popular entertaniers in us,uk and everywhere
The most popular sports in the us are football baseball and basketball.
The Angus is the most popular for beef cows. The Holstein is the most popular for dairy cows.