Passage 2 Questions 6 to 10 are based on the following passage:Humans may not have landed on Mars (火星) justyet, but that isn’t shopping a European company from devising a plan to sendfour people to the Red Planet within the next few years. (78) This project,called Mars One, aims to send a small group of people to Mars in 2022 andeventually establish a permanent colony on the planet. "Everything we need to go to Marsexists," said Mars One co.founder Bas Lansdorp in March 2014. "Wehave the rockets to send people to Mars, the equipment to land on Mars, therobots to prepare the settlement for humans. For a one.way mission, all thetechnology exists." Yet the four astronauts (宇航员) chosen for the trip will be stuck on Mars—forever. And despite MarsOne’s thorough planning, there are a number of challengesthat may prevent the mission from ever taking place. (79) The biggest roadblock could be the mission’s huge cost ($6 billion). However, Lansdorp is confidentthat Mars One will be able to fund the project by selling the broadcast rightsfor the mission and subsequent experiences living on the planet.Those broadcast rights will also play apart in helping to select the people who will be sent to Mars. Lansdorp said the company will hold a selection process similar to a reality show. Lansdorp is expecting at least 1 million applications from people around the world. In additon to the cost, several other potential problems could inhibit (阻止)themission to Mars.“It’s even more challengingto send people there with life support, with food, with air, with all the other things like books, entertainment, means ofcommunication and of providing for their own resources for a long stay onMars," said Adam Baker. senior lecturer in spaceengineering at Kingston University in London. "The sheer size of therockets you’d need to do this would be absolutely colossal.” The word "colossal” in the last paragraphis closest in meaning to （）. A: very large B: very small C: medium D: average