—What do you think of this matter?  —This is a matter of __________ importance. I think.

A ___________ identification card is required when you purchase foreign money from the     Bank of China. 

 _______ to settle into the new environment, he made every possible effort.

Studies show that people are more ______ to suffer from back problems if they always sit before computer screens for long hours. 

Come and see me whenever________________.