79.Due to his health problems, Richard has to _______ hard physical work on his farm.

21.Jack recommended to me a unique restaurant that _______ in seafooD.

20.For the time being, this computer system is still in its _______ stages.

19.The following table includes a list of subjects at the _______ of scientific exploration.

18.The general decided to launch a( ) ______ on the enemy at midnight.

17.We set out to find the truth behind the ______ of the scientist’s disappearance.

16.At the meeting, he tried to _______ the discussion away from criticizing the educational experiment.

15.Jack had a hard time grasping the basic _______ of mathematics.

14.His interview did not go well and his chance of getting the job ______.

13.Jack has no interest whatsoever in ______ an acting career. He loves writing and directing.

12.Do not ______ more responsibilities than you can handle.