$1-\frac{3}{7}+\frac{4}{7}=1-1=0$ 。

    What do you usually do at the weekend? Some people like to 1 at home. But others like to go 2 a walk or play football. My friend Jack works hard in a factory on weekdays. At the weekend, he always 3 the same thing. On Saturday he 4 his car and on 5 he goes with his family to a village by car. His uncle and aunt have a farm there. It isn't a 6 one, but there's always 7 work to do on a farm. In 8, the harvest season, the children help them pick oranges. They also help with the animals and give them their 9. Jack and his wife help in the fields. At the end of the day, they are all 10 and Jack's aunt gives them a big meal.