问题
选择题
-- Lisa was seen ______ an old man go across the street this morning.
--What a kind girl she is!
A．helping
B．helped
C．to help
D．helps
答案
答案：C
题目分析：句意：---今天早上，Lisa被看到扶一个老人过街。---多么善良的女孩啊！看到某人做某事，see sb do, 改成被动语态时，应用be seen to do。故选C。