题目

What do the people usually do on weekends? Some people like to_______ at home, but others like to go out for a walk or play football. Mr. Smith_______ hard in a factory during (在期间) the ______. On weekends, he usually _____the same thing. On Saturday he washes his car and on ______ he goes with his family to a village（村庄）by car. His uncle and aunt _______a farm there. It isn't a big one, but there is always ______to do on the farm. The children help with the animals and give them some ______. Mr. and Mrs. Smith help in the field(田地). At the end of the day, they are all______ 8．科学施肥是实现农业增产的重要手段．硝酸铵（NH4NO3）是一种常用的氮肥，其中化学式量是80．氮、氢、氧三种元素的质量比为7：1：12氮元素的质量分数是35%．