摘要： unconscious
网址：http://m.1010jiajiao.com/timu3_id_2576108[举报]
People knocked unconscious due to not wearing safety belts have a greater chance of dying in these accidents．
When climbing the hill John was knocked unconscious by an ________ rolling stone.
- A.untouched
- B.unexpected
- C.unfamiliar
- D.unbelievable