Achieving a high degree of proficiency in English as a foreign language is not a mysterious _____  without scientific basis.

There is an obvious __________ between the cultures of the West and East.

It is not intelligence alone that brings success but also the _____ to succeed and the courage to believe in yourself.

Gerneally speaking, it is difficult to breathe at a high       of Tibet (西藏).

Much to my         , I’m unable to accept your kind invitation.