锁骨骨折治疗上应采用（）。

A.夹板固定

B.双圈固定

C."8"字绷带固定

D.持续牵引

E.石膏固定

____ you bring _____ to his attention that now students are bearing too heavy a  leaming load(负担) ?   [ ]

A. Why not; that    

B. Why not; this    

C. Why don't; it      

D. Why don't; what