1. Which of the following is an argument? A. Before accepting a job after class hours, I would suggest that you give careful consideration to your course load. Will you have sufficient time to prepare for classes and tests, and will the job produce an excessive drain on your energies? B. Cows can digest grass, while humans cannot, because their digestive systems contain enzymes not found in humans. C. The trade deficit is rising. The cconomy is not improving. D. Every event must have a cause. Since an infinite series of causes is impossible, there must be a first uncaused cause of everything: God. 2. Which is the main connective of the following sentence: (P Q)→R A. - В. . C. - D. 0 3. Which is the main connective of the following sentence: {[-(4-→B) v C]→~D} vE A. - B. → С. v D. +