To select multiple objects easily, which key should be held down while clicking them?

The Shift key is commonly used in many software applications for selecting multiple objects in a contiguous manner. When holding down the Shift key while clicking on objects, it allows the user to select a range of items, creating a continuous selection from the first clicked item to the last clicked item. This is particularly useful when you want to select multiple items that are adjacent or in a sequence.

In contrast, other keys like the Control key are often used for making non-contiguous selections, allowing users to select individual items that are not next to each other. The Alt key typically modifies actions for specific tasks and does not serve the purpose of selecting multiple items in a common user interface. The Command key is specific to Mac operating systems and resembles the functionality of the Control key on Windows, also working for non-contiguous selections. Therefore, the Shift key is the best choice for easily selecting multiple objects in a straightforward and organized fashion.