Which one of the following was the first human to complete an orbit of the Earth in 1961?
A. Valentina Tereshkova
B. Yuri Gagarin
C. Neil Armstrong
D. John Glenn
E. Buzz Aldrin
Which one of the following was the first human to complete an orbit of the Earth in 1961?
A. Valentina Tereshkova
B. Yuri Gagarin
C. Neil Armstrong
D. John Glenn
E. Buzz Aldrin