They were visiting the history museum at one o'clock yesterday afternoon .（对划线部分提问）
问题描述：
They were visiting the history museum at one o'clock yesterday afternoon .（对划线部分提问）
划线部分：visiting the history museum
______ ______ they ______ at one o'clock yesterday afternoon
答
What were,doing
不明白的再问哟,请及时采纳,多谢!