There are hundreds of visitors in front of the Art Gallery to have a look at Van Gogh’s

问题补充：

There are hundreds of visitors in front of the Art Gallery to have a look at Van Gogh’s paintings.

A. waited

B. to wait

C. waiting

D. wait

答案：

A. waited

B. to wait

(答案→)C. waiting

D. wait

解析：此处用现在分词作定语，表示动词正在进行。