31. According to the author, compared with choosing a marriage partner, choosing a travel companion is ______.
A. just as difficult as it
B. is possibly easier than it
C. is perhaps less certain than it
D. is perhaps less uncertain than it
32. Travel will give us a chance to ______.
A. become strong and vigorous
B. testify our friendship
C. see who is our enemy
D. lose a friend
33. The travel companion the author refers to is ______.
A. anybody you meet