[音频]16. A) How space research benefits people on Earth. B) When the International Space Station was built. C) How many space shuttle missions there will be. D) When America's earliest space program started.17. A) They tried to make best use of the latest technology. B) They tried to meet astronauts' specific requirements. C) They developed objects for astronauts to use in outer space. D) They accurately calculated the speed of the orbiting shuttles.18. A) They are expensive to make. B) They are extremely accurate. C) They were first made in space. D) They were invented in the 1970s.