题目

在煮过和没煮过的土豆片上分别滴几滴过氧化氢。在土豆片M上出现泡沬，在土豆片N上没有泡沫，以下哪一项是正确的解释（ ） A . 土豆片M是煮过的，因为过氧化氢只影响淀粉分解成单糖 B . 土豆片M是煮过的，因为在没煮过的土豆片中酶能使过氧化氢不起作用 C . 土豆片M是没煮过的，因为植物中含有酶，使过氧化氢分解，但酶会在高温中失效 D . 土豆片M是没煮过的，因为过氧化氢分解土豆中的酶This is a photo of Ben’s family. He has a big family. Look! Ben’s grandparents are on the sofa. They are workers. They are old, so they don’t work now. Ben’s father is a doctor. He works in a hospital. He often drives his car to work. Ben’s mother is a teacher. She teaches English in our school. The man in white is Ben’s uncle. The young woman in red is Ben’s aunt. They are office workers. Ben’s family live in Beijing now. Ben and I are classmates. We are good friends.根据短文内容，选择正确答案。小题1:What does Ben’s grandfather do?A．A doctor.B．A teacher.C．A farmer.D．A worker.小题2:What do Ben’s parents do?A．They’re doctors.B．They’re teachers.C．His father is a doctor and his mother is a teacher.D．His father is a teacher and his mother is a doctor.小题3:Where do Ben’s uncle and aunt work?A．In an office.B．On a farm.C．In a hospital.D．In a school.小题4:Where do Ben’s family live now?A．In Canada.B．In China.C．In England.D．In America.小题5:Which of the following is NOT true?(下面哪一个选项不正确)A．Ben’s family is big.B．Ben and I are in the same class.C．Ben’s mother is my Chinese teacher.D．Ben’s aunt is in red in the photo.