When asked about the secret about staying young, he said  that a balanced diet ____ with exercise

was the recipe   for a healthy life.    [ ]

A. conducted  

B. concluded  

C. combined  

D. connected

感染艾滋病病毒(HIV)的孕妇引起胎儿感染，这是经

A．医源性传播
B．垂直传播
C．食物传播
D．接触传播
E．飞沫传播