Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to create contour lines using sketchup [title] Click on the add imagery icon. [step] Go to wherever you want to get your contours from in the screen that comes up. [title] Draw a rectangle that is the size of the contours that you are creating.

Ending1: [title] Click on the move tool and holding down ctrl and make a copy and make sure it is directly above the previous layer. [step] Type in the number that you want for contour lines. Ending2: [step] You want your curves to run horizontally, and not vertical. [substeps] Back away from the rectangle, if you can. Ending3: [title] Finish the rectangle with a line bigger or smaller than the contours that you are making. [title] Go back to the image that you just created and you will see that it is now the outline of what you have drawn with your brush. Ending4: [title] Add lines inside of the rectangle. [step] Each part of the rectangle needs to be about 1.05x1 centimeter for contour lines.

Answer format: ending1/ending2/ending3/ending4