Inference

If a metalworker from 3,000 years ago could somehow travel forward in time, he would recognize virtually every step of the lost-wax process that today is used to cast titanium for jet engines.

• Metalworking has changed very little in 3,000 years.

• Titanium has been forged for thousands of years. 

• The lost-wax method of casting metal is very old.

When apple growers talk about new varieties of apples. They don’t mean something developed last month, last year, or even in the last decades. 

• Apple growers have not developed any new varieties in recent decades. 

• Some varieties of apples can be developed in a short time, but others take a long time. 

• New varieties of apples take a long time to develop.

High levels of serum cholesterol are no longer a problem only for adults. 

• High levels of serum cholesterol are no longer a problem for adults.  

• Only children have a problem with high levels of serum cholesterol.

• High serum cholesterol affects both adults and children. 

Alpha Centauri, one of the closest stars to Earth, is just 4.3 light years away. It can be seen only from the Southern Hemisphere. However, the closest star (other than our own Sun, of course) is a tiny red star, Proxima Centauri, which is not visible without a telescope. 

• Proxima Centauri is the closest star to Earth.

• Alpha Centauri is invisible from Earth without a telescope.

• Proxima Centauri is closer than 4.3 light years from the Earth.

Compared with the rest of its brain, the visual area of a turtle’s brain is quite small, since turtles, like all other reptiles, depend mainly on senses other than sight. 

• No reptile uses sight as its primary sense. 

• Animals that depend on sight all have larger visual areas in their brain than turtles do. 

• The visual area of other reptiles’ brains is smaller than that of turtles. 

An old but still useful proverb says, “beware of oak, it draws the stroke.” In general, trees with deep roots that tap into groundwater attract more lightning than do trees with shallow, dry roots. Oaks are fifty times more likely to be struck than beeches. Pines are not as safe as beeches but are still much safer than oaks. 

 

• Pine’s roots are deeper than beeches’, but not as deep as those of oaks.

• The deeper the root, the safer the tree. 

• The roots of oaks are fifty times deeper than those of beeches.