题目

某课外小组在25℃、不同pH条件下,用人体的胃蛋白酶和胰蛋白酶分别催化蛋白质水黑，实验结果如下，相关叙述正确的是 A.向pH为6的反应容器中滴加盐酸后，胃蛋白酶的活性会升高 B.两种酶混合使用的催化效率大于两种酶单独作用的效果 C.本实验中pH和酶的种类是自变量，温度是无关变量 D.升高温度两种酶的最适PH都会增大Mary is the hostess of her school radio station. She hosts New Movies once a week for ten minutes, and Travel Around the World for fifteen minutes each time, once a week too. But this time, she is talking to the world on web radio. Her district（地区）started web radio for kids this month. Every weekday, during lunchtime, students make a 30-minute Internet radio programme. The schools in the district take turns（轮流）to host the programme.Mary says her job is very important. “In the past, only the students in my school could hear me, but with the web, students all over the world can hear my voice! I am sure that I can make friends with many people through my warm and easy talk,” she said.Besides Mary, other kids from her school do a lot of work, too. After they decide on a story, some kids begin to surf the Internet, while the others begin to think of the programme ideas or write the stories. The programme is made on a computer. Listeners can then hear it by visiting the website.The Education Bureau（教育部）began to prepare for web radio last year. An official（官员）said, “We want to let the kids know how to make full use of the Internet instead of（代替）only playing web games. ”1.How long does this web radio programme last every week?A. Fifteen minutes. B. Twenty-five minutes.C. Half an hour. D. Two and a half hours.2._________ host the web radio programme.A. Mary herself B. Mary and her schoolmatesC. All the schools in the district D. Education Bureau officials3.How can listeners hear the web radio programme?A. By visiting the website. B. By going to school.C. By listening to the radio. D. By watching TV.4.What does the underlined phrase “make full use of” mean in Chinese?A. 完全掌握 B. 充分利用 C. 灵活使用 D. 正确操作5.Which of the following sentence is TRUE?A. This web radio programme is mainly for the old men.B. Mary is in charge of（主管）the web radio.C. Only children take part in the web radio.D. Kids can learn lots of stories from the web radio.