Well, the smell could be from a spillage, which when your moving goes to the main petrol tank. another explanation is your mum.
He thought he was well hidden, but the top of his head was visible.
The external genitalia aren't anything readily visible. Initially, the only visible difference between males and females is the ano-genital distance. See related links.
Every 76 years, on the average, throughout recorded history. Most recently in 1986. Expected to be near enough to be visible again by around 2061.
The law that "A body initially at rest remains at rest.", since no vibration is visible from here.
This is a question for a vet.
Symptoms initially are mild and include tremors while stretching hands, muscle cramps after exertion, and fasciculations (visible muscle twitches).
Well, as the name implies, visible areas of the crust are areas that you can see. These are areas that are either very new, resulting from recent vulcanism; or areas which have been exposed by weathering and erosion. Non-visible parts of the crust are just that - not visible to the eye. This is either because they have formed recently, but many miles underground; or they are just too old to have been efficiently exposed by weathering and erosion.
Make sure every single piece of mud is well sanded and no seams are visible.
Cirrus clouds are often used to a couple different types of weather. It is thought that if only a few are visible in the sky that the weather will be moderate. It is also thought that if many of them gather, rain is on the way.
UV rays are part of electromagnetic spectrum just like light. Some rays can be detected by the eye and some cant. The sunlight we see is the visible part of this spectrum that is why it is called visible light. Initially only light would reach the earth but now because of ozone depletion even UV rays reach the earth. So basically they are invisible because they are not part of visible light.
Halley's comet last passed through the inner solar system ... becoming bright enough to be visible ... in the mid 1980s. It's not expected to be visible again, even with significant optical enhancement, until some short time before 2060.
Of a sort, if you consider that they are the Gemini stars; thought to be visible half a year above, and spending half a year below in Hades.