Bill is an English boy. He is twelve. He lives in China with his family. There are four people in his family. They are his father Jack Cliton, his mother Catherine and his little sister Abby. He has a yellow dog. Its name is Barbi. His father is mending his bike. What is Bill doing? Ah, he is doing Chinese homework. He can't speak Chinese very well. But he loves Chinese very much. Bill's father works in middle school. He is an English teacher. His mother is in a TV factory. Bill and his sister go to the same school.

在某市组织的大型商业演出活动中，对团体购买门票实行优惠，决定在原定票价基础上每张降价80元，这样按原定票价需花费6000元购买的门票张数，现在只花费了4800元．

化学农药是用化学方法合成的一大类物质，有杀虫剂、杀菌剂、除草剂和植物生长调节剂等。下列关于甲酯除草醚 的叙述正确的是(  )