(单选题)15: Dangers and ethical issues come into play when scientific research _______. A: Has been doing B: is done C: does D: did. ...

(单选题)9: There is no easy answer __ the most basic question. A: on B: from C: off D: to ...

(单选题)3: Susceptible A: Easily influenced B: doubtful ...

(单选题)17: 第四次作业问题16 A: On the table B: Behind his back C: Under his bottom D: On his lap ...

(单选题)5: 第四次作业问题15 A: Avoid eating any food B: Prepare the right type of pie to eat C: Wash his hands thoroughly D: Practice eating a pie quickly ...

(单选题)19: 第三次作业问题17（作业音频请到课程公告里下载） A: It takes skill. B: It pays well. C: It's a full-time job. D: It's admired worldwide. ...

(单选题)13: 第三次作业问题18 A: A mother with a baby in her arms. B: A woman whose bag is hanging in front. C: A lone female with a handbag at her right side. D: An old lady carrying a handbag on the left. ...

(单选题)7: 第三次作业问题19 A: The back pocket of his tight trousers. B: The top pocket of his jacket. C: A side pocket of his jacket. D: A side pocket of his trousers. ...

(单选题)1: 第三次作业问题14 A: Children don't get enough education in safety. B: Children are keen on dangerous games. C: The playgrounds are in poor condition. D: The playgrounds are overcrowded. ...

(单选题)9: 第二次作业问题15 A: A radio announcer. B: A bank employee. C: A car mechanic. D: A movie actor. ...