22.Some people are worrying about the possibility ________ cellphones could be responsible for a range of illnesses, from rashes to brain tumors.

A．that

B．why

C．how

D．Whether

商业步行街[ ]

A、非机动车可以通行

B、以批发商业为主

C、商业步行街往往具有商业贸易、旅游、休闲、文化娱乐等功能

D、商业步行街是以休闲娱乐为主的专门区域