Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to add toolbars to your browsers [title] Launch firefox. [step] Double-click on the browser's shortcut icon on your desktop to launch it. [title] Open the menu.

Ending1: [step] On most browsers, scroll down and select firefox on the menu panel. You will see many options, such as split-screen or full screen. Ending2: [step] Locate the " search engines " folder on your bottom toolbar, and click on it. The menu panel should expand on-screen and show a list of search engines that you can browse. Ending3: [step] It's the green gears icon typically found on a lower-right corner of the browser window, typically located on the dock or inside of the left panel. This displays a menu that lists settings for your running programs. Ending4: [step] Click the menu button at the upper-right corner of the browser window, which is an icon of three rows stacked upon each other. This will open the menu where you can customize your firefox browsing experience.

Answer format: ending1/ending2/ending3/ending4