阅读短文回答问题。 What do 17-year-old boys usually do ? Play computer games, read books or play basketball? But to Zac , all interests in   his  life are from the sea. He is a 17-year-old  US  sailor.   After  a   hard 13-mon th voyage, he and his 11-metre sailboat arrived at a Southern California har bour. He becomes the youngest person to sail around the world alone. When Zac was just a child, he had a dream-driving his own boat to travel around the world . so he saved all his pocket money . When he was 16 years old, he had 6,500 dollars. He bought a sailboat, and started his journey with the support of his father, a ship builder. On June 14, 2008, Zac left Marin Del Rey, south of Los Angeles, and celebrated his 17th birthday at sea near Africa's Cape of Good Hope. During his 28,000-mile journey , he came over many difficulties. When he came back home , he was welcomed by a lot of people. It is said fewer than  250 Pe ople  have sailed around the world alone. The number of reaching the top of Mount Everest is three  times as large  as the number of sailing around the world alone. 参考词汇:voyage航海    harbour 港湾    sail 航行  Mount Everest珠穆朗玛峰 Cape of Good Hope 好望角 1.Where are Zac's interests from? ______________________________________________________________________ 2.How long did he spend in traveling around the world? ______________________________________________________________________ 3.What was his father's job? ______________________________________________________________________ 4. Was his journey difficult? ______________________________________________________________________ 5. Which number is smaller ,the number of reaching the top of Mount Everest or the number of sailing around the world alone? ______________________________________________________________________