No person _______ carry a mobile phone into the examination room during the national college Entrance Examinations.

Seeing his mother seemed uninterested in the story and _______she remained _______with her cellphone, he chose to massage her back.

Taiyuan，a city in North China，was struck by a heavy snowfall last week，________serious traffic problems.[ ]

Can you tell me by whom the speech next Friday—Mr. Green, our geography teacher.

It is sometimes difficult for a newly established corporation to ______ the changing demands of the market.