As more companies start selling tickets to travel into space，people are asking：Who gets to call themselves an astronaut？
     It is no longer an easy question to answer.People （1）

who/that

who/that

are very rich are able to pay to go into space.Russian space officials have been calling them spaceflight（2）

participants

participants

（participate） for many years.
    The new supervisor of the U.S.jye.ai agency NASA is Bill Nelson.He does not consider（3）

himself

himself

（him） an astronaut although he（4）

spent

spent

（spend） six days in space in 1986.He was a congressman tjye.ain.He told The Associated Press that he believes the term "astronaut" should be（5）

for

for

professionals.
    Axiom Space's Michael Lopez-Alegria is（6）

a

a

former NASA astronaut.He will join three businessmen on a SpaceX spacecraft on a trip to the space station（7）

planned

planned

（plan） for January.They each paid ＄55 million for the trip.Lopez-Alegria said they do not consider themselves space （8）

tourists

tourists

（tour） since they will be doing research.
    Recently，Axiom Space said there（9）

will be

will be

（be）a second flight to the space station next year.Peggy Whitson will be on that flight.She is a（10）

retired

retired

（retire） NASA astronaut who has spent 665 days in space.