A、Supportive. B、Opposed. C、Optimistic. D、Skeptical. B讲座中提到，有更多的美国人反对而不是赞成政府支持在人类胚胎上测试基因编辑技术。大约25％的人没有意见。原文中提到，匹兹堡博物馆的工作人员Jaron K

A public opinion study says that most Americans would accept the use of gene-editing technology to create babies who are protected from some diseases. But the same study finds that Americans do not support changing the genetic structure, or DNA, of children so that they are faster, taller or more intelligent. The research was carried out by the Associated Press-NORC Center for Public Affairs Research. The opinion study suggests that many people are concerned about what gene-editing means for the future. More than 1000 people were questioned in the study. The researchers said Americans value the medical promise of technology that could change the genetic qualities human parents pass on to their children. But they worry whether it will be used in a moral way.
    Gene editing takes out a part of DNA to remove, replace or repair a gene. Changes to adult cells only affect the person being treated. But editing genes in eggs, sperm or embryos can change the resulting child in ways that can be passed to future generations. Because of its important effects, international science guidelines say gene-editing should not yet be tested in human pregnancies. Scientists say more laboratory research is needed to prove whether or not it is safe. Dr. Robert Klitzman studies biological research rules. He noted that, if fertility clinics start to edit the genes of embryos, there will be hard choices to make about what conditions can be changed. What if scientists could identify genes involved with depression or autism or high body weight? Would they be acceptable to edit? "It’s one thing to look at the extremes of fatal diseases versus cosmetic things, but in the middle are going to be these very different issues, " Klitzman said.
    More Americans oppose than approve of government support for testing gene-editing technology on human embryos. About 25 percent of them have no opinion. Jaron Keener, a Pittsburgh museum worker, said that he opposes the research because he fears it would not be used only to fight disease. "I just don’t have a lot of confidence people wouldn’t use it for their own gain, " he said. The study suggests a lack of trust in the technology. About one-third of Americans think gene editing will be used before it is fully tested. Nearly 90 percent of the people in the study thought that the technology will be used for the wrong reasons.
    Questions 19 to 22 are based on the recording you have just heard.
    19. What does the public opinion study find?
    20. What are Americans concerned about the gene-editing technology?
    21. What does the international science guidelines say about gene-editing?
    22. What is the museum worker Jaron Keener’s attitude towards gene-editing?