both you and he are careful否定句

问题描述:

both you and he are careful否定句
they have been to Nanjing twice对划线部分提问(划线的是twice)
____ _____ ____ have they been to Nanjing

both you and he are careful否定句
Neither you nor he is careful
they have been to Nanjing twice对划线部分提问
How many times have they been to Nanjing?