Finding the ______look on the student’ s face, the professor felt _____about his explanation. 

We'll have to wait a ________ two weeks to know the examination result.

  Of the Kar’s boys, Robert is the richest; in other words, Andrew and Krist are _____.

In the new curriculum, some courses are        , while others are optional for middle school students.

Driving a car without insurance can have _____ consequences.