Bottle-feeding babies can ____ adult obesity, says study Research shows using formula can

cause health problems in later life.       [ ]

A. lead to      

B. stick to    

C. object to    

D. turn to

引起疯牛病和人类克雅病、库鲁病等的病原因子是（）

A.朊粒

B.病毒

C.拟病毒

D.类病毒

E.衣原体