As we all know, it was ____ that resulted in the terrible car accident. [ ]

A. because of her carelessness        

B. her being careless 

C. because she was careless          

D. she was so careless

输血速度成人一般调节在每分钟_____ml，老年人或心脏病人每分钟_____ml，儿童每分钟____滴左右。