问题补充：
President Hu Jintao has met with UN Secretary General Ban Ki-moon at the Great Hall of the People in Beijing. President Hu welcomed Bans China and his attendance at the Shanghai World Expo.
A. visiting; visit
B. to visit; to visit
C. visited; visiting
D. visiting; visited
答案：
(答案→)A. visiting; visit
B. to visit; to visit
C. visited; visiting
D. visiting; visited
解析：考察词性。本题第一空中使用visiting来访的，该词修饰名词UN Secretary General Ban Ki-moon，指来访的联合国秘书长潘基文。第二空中的visit是一个名词，指潘基文这次来访中国。句意：胡锦涛主席在北京的人们大会堂接见了来访的联合国秘书长潘基文。胡锦涛主席欢迎潘基文来访中国和参加上海世博会。要分清词性和具体的词义。故A正确。
