Listen to the following passage. Write in English a short summary of around 150-200 words of what you have heard. You will hear

As companies increasingly test new drugs in other countries, they are struggling to decide what, if anything, they owe the patients who served as test subjects. Some companies have chosen not to sell their drugs in the countries where they were tested; others have marketed their drugs there, but few patients in those countries can afford them.
    The issue is especially difficult when it comes to drugs that do not save lives but can vastly improve the quality of life. Nobody knows for sure how many patients in other countries have had to forgo drugs that improved their lives when clinical trials ended, and companies do not give out patients’ names, to protect their privacy. But the issue is very much on the minds of company researchers and executives.
    Ethicists say that they, too, are troubled but that their field has reached no consensus on what companies should do. "Do we have an obligation to everyone in the trial or to everyone in the community, the province, the nation, the region of the world?" asked Dr. Ruth Faden, the director of the Phoebe R. Berman Bioethics Institute at Johns Hopkins University. "We haven’t really figured this out."
    Yet, Dr. Faden said, "many physician investigators feel uncomfortable with the idea of using patients in studies and then not being able to continue to help them when the trial ends."
    Companies must make business decisions about where to market their drugs, figuring out whether they can earn enough money to justify applying for approval, setting up business offices and hiring a sales force. If they decide not to market a drug in a given country, they are unlikely to provide it to patients there free of charge. To provide a drug for what medical professionals call compassionate use, companies must set up a distribution system, train doctors to administer the drugs, monitor patients for adverse effects and track the results.
    Whether to undertake a compassionate-use program for drugs that improve the quality of life but do not prolong it poses "a delicate question", said Tony Plohoros, a spokesman for Merck, a company that has systems to distribute lifesaving drugs in poor countries where there is a need.
The issue is especially difficult for small companies that as yet have no products on the market. A small company cannot afford to set up a marketing system in countries where few can buy the drug, or a distribution system to give its drugs away.
    In the United States, patients who participate in clinical trials often continue to receive the drug being tested until it is approved. After that, they can buy it or, if they cannot afford it, apply to special programs that most companies offer to help people who could not otherwise get drugs they need.
    But with the exception of AIDS drugs, which companies provide free or at low cost to patients in poor countries, there is no industry consensus about what to do internationally, especially when drugs are not lifesaving. And even when companies market their drugs in poor countries, they tend not to set up a system to give the drugs away to study subjects after a clinical trial ends.
    Ethicists acknowledge that companies are businesses and accountable to investors.
    But on the other hand, Dr. Gostin said, there is something troubling about "parachute research", in which a company drops into a country, conducts its research and then leaves.
    "It raises the question of what ethical obligation, if any, there might be to give back and make sure there is access to the drug after the trials are over," Dr. Gostin said.
    The participants in a study take a risk to help a company determine if its drug is safe and effective, he said, and "it seems to me that there is an ethical obligation to give back."