19．Are you a fan of traveling？Well，in 20years，there may be a new place for you to spend your v（66）acation the moon．Last month，the European Space Agency （ESA） published ideas for b（67）uildingan international moon village by 2030．The village aims to open the door for deeper space exploration，and it will a（68）lso be a tourist center． In 1969after US astronaut Neil Armstrong first arrived on the moon，he said the famous w（69）ords"One small step for a man，one giant leap for mankind"．A（70）ccording to the head of the ESA，Johann，the moon village could be"the next giant leap for mankind"，because the technology for this is about 20years away from coming true．One of the biggest challenges is getting the building materials into space w（71）ithout costing too much，said Matthias from the German Aerospace Center．Scientists s（72）uggest using the ice water and rocks on the moon to print 3-D building materials，so people don't have to carry e（73）verything from the Earth．When asked why the ESA chose the moon rather than Mars as the next goal，Johann said it's b（74）ecause the moon is about 144times closer to the earth than Mars．The ESA i（75）nvitedthe US，Russia，China，India，Japan and some other countries to join in its moon plan．It hopes that"in the future，the moon can become a place where the nations of the world work together"．
