For centuries, people have dreamed of leaving the Earth and traveling through space to visit the moon and explore other planets and stars. During the past thirty years, some of these dreams have become realities. Spacecraft have orbited the Earth and sent back data to ground-based scientists. They have traveled to other planets and transmitted images and information that have helped to expand our knowledge of the solar system. People have gone into space to orbit the Earth and even to visit the moon. What word in this paragraph helps you to know the author’s attitude towards space travel?
a. dreamed
b. helped
c. traveling
d. a and b