—How about buying Sam a mobile phone? After all,  he isn't a boy any more.  

—I think it necessary,  for we sometimes want to make sure if he       home for dinner.  

A. will come

B. comes

C. has come

D. would come

对于金刚烷胺治疗流感，正确的是（）

A.有抑制甲型流感病毒的作用

B.缩短临床发热时间，减轻症状，加速疾病恢复

C.对乙型流感病毒无作用

D.有一定的中枢神经系统副作用

E.老年患者剂量加倍