听力原文： China has agreed to share 20 virus samples from poultry killed by bird flu, in an effort to help scientists trying to develop a vaccine, the WHO said. WHO officials in Beijing said Chinese authorities had granted WHO's request for up to 20 live samples, which will be analyzed in international laboratories to improve understanding of the killer virus. The two sides are working out the logistics, including how to ship the samples and which lab they will go to. The shipment is 'significantly larger' than the last one China provided, which consisted of five live viruses from poultry in 2004. WHO enjoyed good cooperation with China's Ministry of Health, which has shared viruses from human cases, but confronted problems trying to convince the Ministry of Agriculture to share samples. Through negotiations, the two sides worked out an arrangement that will give the scientists due credit and involve them in subsequent research whenever possible. WHO officials expressed the hope that the agreement could open the way for more regular sharing of viruses, which is important to determine the different types of strains of the deadly bird flu virus that exist and how they affect humans differently. China has reported 34 outbreaks among poultry since the beginning of last year and 15 confirmed human cases of bird flu, resulting in 10 deaths. The virus has killed more than 100 people worldwide since 2003, mostly in Asia. It has spread from Asia to Europe and Africa in recent months. (4)