I’m very ________ about expressing my opinions in public in case I may make mistakes.

Unemployment in USA is        to remain high in 2010, and possibly for the next few years.

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

We should do what we can to save those_________ species, for example, the tiger, an animal which was considered_______ to humans.

 ___ with various research projects, that scientist can’t even find time to visit his parents.