Katherine Johnson，a brilliant mathematician at NASA （美國國家航空航天局），began working on the space programme in the 1950s.Many of NASA's first missions were made possible by her amazing calculations（計算）.
   As a child，she loved to count.Her father placed great importance on education and insisted all four of his children go to college，working overtime to pay for it.Johnson said this atmosphere was important to her success. "I was always around people who were learning something.I liked to learn，" she said.
   Johnson graduated from high school at 14 and college at 18.In 1953，Johnson started to work for NASA，doing the maths that powered engineers' work.Then，because of her outstanding talent，she was moved to work on rockets with an all-male flight research team.As for Johnson，her calculations contributed to many of NASA's most important projects.In 1961，with the help of Johnson's work，Alan Shepard became the first American to go into space.Johnson also lent her unbelievable talent to the success of the Apollo 13，which had trouble getting back to earth.She worked hard to calculate a safe path back to earth for the astronauts.
   Johnson retired in 1986，but her huge contribution to the space programme has only been reaching the public attention for the past few years.Part of that is because，as she is the first to admit，science is based on collaboration. "I never took any credit because we always worked as a team；it was never just one person，" she said in a 2010 interview.
   Earlier this year，NASA named a new data centre after her.She was also given a Silver Snoopy Award，which recognizes "outstanding performance，contributing to flight safety and mission success".

（1）How does the author explain Johnson's help to NASA？

B

B

A．By comparing differences.
B．By providing examples.
C．By showing numbers.
D．By giving reasons.
（2）What does the underlined word in Paragraph 4 mean？

C

C

A．Experience.
B．Research.
C．Teamwork.
D．Talent.
（3）What can we infer from the passage about Johnson？

D

D

A．She travelled to space with the Apollo 13.
B．She lived a rich life when she was young.
C．She has been widely known since her retirement.
D．She used to be the only lady in the research team.
（4）What is the passage mainly about？

A

A

A．Johnson's great contribution to NASA.
B．Respectable awards honoured to Johnson.
C．The importance of education for Johnson.
D．NASA's achievements in exploring space.