1) Cows have best friends and can become stressed if they are separated.

2) The first sound film, "The Jazz Singer," was released in 1927 and marked the transition from silent movies to "talkies."

3) J.K. Rowling's "Harry Potter" series of books has sold over 500 million copies worldwide and has been translated into 80 languages.

4) The role of lobbyists in politics involves representing the interests of specific groups or industries and advocating for favorable policies or influencing decision-making processes within government institutions.