Don't be conspicuous. In the combat zone, it draws fire. If your sergeant can see you, so can the enemy. Complex problems have simple, easy to understand wrong answers. The bigger they are, the harder they hit.
Hot glass looks exactly the same as cold glass.
If it stinks, it's chemistry.3. If it doesn't work, it's physics. To err is human, but to really foul things up requires a computer. An object in motion will be heading in the wrong direction.2. An object at rest will be in the wrong place.