Yosemite National Park has the best collection of native plants. ______, it contains a great number of trees and flowers from overseas.
The illness from which Mary is suffering has now been _____ as hepatitis (肝炎).
A completely new situation is likely to _____ when the school leaving age is raised to 16.
. I must go now. _____, if you want that book I'll bring it next time.
Achieving a high degree of proficiency in English as a foreign language is not a mysterious _____ without scientific basis.
They were so far away that I couldn't _____ their faces clearly.