1.   The professor explained the poem to the class.

2.   A professor of biology explains the inner workings of the cell, and how all human traits are transmitted.

3.   A Sorbonne professor explains his work with language-deficient young people.

4.   The professor explains treatments for sleep apnea.

5.   The professor explained that the answers must be complete, and the test will be timed.

6.   The professors explained that the economy of the United States has a great impact on the Canadian economy.

7.   The psychology professor explained that the overwhelming attention of society and the news media on family tragedies could affect the next generation.

8.   The University of Chicago professor explained how people often stay one step ahead of governments by anticipating changes in conditions or policies.