（1）Who did Mary go to the Great Wall with？
A.Her friends.
B.Her sister.
C.Her parents.
（2）Why did the ancient emperors build the Great Wall？
A.To let the world remember them.
B.To protect their country.
C.To let China become strong.
（3）What is the most famous part of the Great Wall!？
A.Jiayuguan.
B.Badaling.
C.Juyongguan.