To select an object, do the following:
Every time you click on an object, a previously selected object
is deselected by default. In order to select several objects,
you can hold down the Ctrl
key while clicking on objects.
In that case, previous selections are not removed.
Alternatively, hold down mouse button 1 and move the mouse pointer. This will select all objects under the mouse and is called swipe select.
For related information, select from the list below: