对括号部分提问:(格式在下)原句:They flown to Shanghai (once a month)格式: ______ _______ _________( 3格空格 ) they fly to Shanghai.
问题描述:
对括号部分提问:(格式在下)原句:They flown to Shanghai (once a month)
格式: ______ _______ _________( 3格空格 ) they fly to Shanghai.
答
How often did
就是问频率的意思