Copy and Paste – Select the object to copy and paste, then on a keyboard use “Ctrl” + “C”(Windows) or “Command ⌘” + “C” (Mac) to copy the selected object. Once you are on the proper page in your activity, use “Ctrl” + “V”(Windows) or “Command ⌘” + “V” (Mac) to paste the object.
Select multiple objects — Press "Shift" + Click to select more than one object at a time.
Delete — Select an object and press the “Backspace” or “Delete” button on the keyboard.