一、单选题(共20小题;每小题1分，满分20分)
1. It is_______ unusual thing for us to find _______ UFO.
A. a; a B. an; an C. a; an D. an; a
2. Shanghai is east of China and north of Guangdong.
A. in the;不填 B. in; to the C. in the; on the D. to the; on the
3. —Why do you like keeping goldfish as your pet?
