Achieving a high degree of proficiency(精通）in English as a foreign language is   not a mysterious _______ without scientific basis.

A．process

B．practice

C．procedure

D．program

舒立迭与口服沙丁胺醇相比（）

A.起效更快

B.起效较慢

C.持续时间更长

D.持续时间较短