They saw a Bejing opera (last week)

问题描述:

They saw a Bejing opera (last week)
对框出来的部分提问:____ ____ they ____ a Beijing opera?

(When did ) they ( see ) a Beijing Opera
分析:问时间用WHEN,实义动词作谓语,一般过去时要加助动词DID,原来的动词要用原形,即saw -> see.
加油!不明白再问!