Selecting and transforming objects

1. You can select an object that is a part of a group by clicking it while holding down the Ctrl key.
2. If you marquee-select objects with the Alt key down, then you select objects that are not only surrounded with the marquee completely but also only "touched" with it.
3. To select an object completely obscured by another object, just click where the underlying object should be with the Alt key down.
4. To stretch an object from its center hold down Shift, and drag one of the side selection handles. To stretch an object in increments of 100%, hold down Ctrl as you drag a selection handle. To stretch an object vertically and horizontally at the same time, hold down Alt as you drag one of the corner selection handles.
5. You can rotate and skew an object freely if you hold down Alt key while transforming it.