What does an arrow after a command indicate

Technician a says that if a valve is open when a piston rises to the very top of a cylinder, the piston may actually strike the valve head and cause serious engine damage. technician b says if the camshaft is located in the engine block, then the engine is called an overhead valve engine, ohv engine, or an in-block camshaft. who is right? a. b only b. both a and b c. a only d. neither a nor b

Write a modular program (no classes yet, just from what you learned last year), that allows two players to play a game of tic-tac-toe. use a two-dimensional char array with 3 rows and 3 columns as the game board. each element of the array should be initialized with an asterisk (*). the program should display the initial board configuration and then start a loop that does the following: allow player 1 to select a location on the board for an x by entering a row and column number. then redisplay the board with an x replacing the * in the chosen location. if there is no winner yet and the board is not yet full, allow player 2 to select a location on the board for an o by entering a row and column number. then redisplay the board with an o replacing the * in the chosen location. the loop should continue until a player has won or a tie has occurred, then display a message indicating who won, or reporting that a tie occurred. player 1 wins when there are three xs in a row, a column, or a diagonal on the game board. player 2 wins when there are three ox in a row, a column, or a diagonal on the game board. a tie occurs when all of the locations on the board are full, but there is no winner. input validation: only allow legal moves to be entered. the row must be 1, 2, or 3. the column must be 1, 2 3. the (row, column) position entered must currently be empty (i. e., still have an asterisk in it).

Which of these is most responsible for differences between the twentieth century to the twenty-first century?