MOSCOW(Reuters) – Russia hopes the United States will extend the deadline to retire its space shuttles beyond 2011 and has heard unofficially it is possible, the head of Russia's space agency was quoted as saying on Friday. The U.S. space agency NASA(美国宇航局) plans six more missions by its fleet of aging space shuttles by late next year or early 2011 after the construction of the $100 billion International Space Station (ISS) is completed. The shuttles will then be retired. But the head of Roscosmos, Russia's space agency, said he would prefer to see further shuttle missions to the Space Station, now in orbit 360 km (225 miles) above Earth. 'From some sources we have learned that it is possible to extend the life of the shuttle beyond 2011,' Roscosmos chief Anatoly Perminov was quoted by RIA news agency as saying. Reuters was not invited to the briefing(简报会). 'Then the situation would change substantially and it would be possible to work jointly with the Americans, unlike now, when the main burden (for the ISS) lies with the Russian side,' Perminov was quoted as saying by Interfax. Perminov said he had not been told this through official channels, Interfax news agency reported. He added that NASA's new chief and former astronaut Charles Bolden would visit Russia's Baikonur cosmodrome on September 30 in his first foreign trip. NASA's future strategy is currently under review with the main focus on possible flights to Mars. It is also encouraging a private space taxi project to the ISS. NASA's current plan, conceived under former President George Bush after the Columbia accident, is to complete the space station, retire the shuttles and build new spaceships. A new rocket and capsule to transport astronauts to the ISS is also being dev eloped but will not be operational until about 2015. Until then, NASA will rely on Roscosmos and must pay $50 million per seat for flights to the ISS by Soyuz capsules. The U.S., Russian and Chinese governments are the only entities currently capable of human orbital space flight, although several U.S. companies are developing vehicles and support services to do so. 小题1:What does the underlined word “this” in Paragraph 2 refer to? A．NASA agrees to extend the life of the shuttles beyond 2011. B．Reuters was not invited to the briefing. C．The US would work jointly with Russia. D．NASA’s new chief would visit Russia’s Baikonur cosmodrome. 小题2:NASA’s current plan includes all the following EXCEPT . A．completing International Space Station B．flights to Mars C．retiring the current space shuttles D．building new spaceships 小题3:If the US doesn’t extend the life of the shuttles beyond 2011, . A．International Space Station will be quit B．Roscosmos will have to build more spaceships C．NASA will have to quicken the development of the new rocket and capsule D．Roscosmos will be burdened with the transportation to ISS 小题4:We can infer from the passage that . A．China has already been involved in the project of flights to Mars B．it is certain the NASA will retire the current space shuttles as planned C．NASA is considering Russia’s suggestion D．NASA will be able to provide a private space taxi project to the ISS by 2015.