A、Three. B、Four. C、Five. D、Six. B细节题。文中提到，the four pirates released the ship and its crew(四名海盗释放了船只及船上的船员)，由此可知，劫持事件中共有四个海盗，故答案为

American government lawyers this week brought criminal charges against a young Somali man in connection with a ship hijacking earlier this month. They say Mr. Muse is the only survivor of a hijacking attempt on an American ship off the coast of Somalia on April the eighth.
    In the hijacking, the four pirates released the ship end its crew. But they took the ship’s captain hostage in a small boat. Four days later, American Navy forces killed three of the hijackers and rescued the captain, Richard Phillips. Mr. Muse was flown from Africa to New York City, where he was charged Tuesday with five crimes, including piracy and hostage-taking.
    A New York federal court judge has ruled that Mr. Muse is at least 18 years old and can be tried as an adult. But his mother has said he is just sixteen years old. That could create a problem for government lawyers seeking the most severe punishment for the accused — spending the rest of his life in prison. International law has less severe punishments for criminals under the age of 18.
    Confirming Mr. Muse’s true age is difficult because birth documents are rare in Somalia. The country has not had an effective central government for almost 20 years.
22. Who is Mr. Muse?
23. How many pirates were involved in the hijacking?
24. What can we learn about the hijacking from the passage?
25. Why is it difficult to confirm Mr. Muse’s true age?