Plutonium is much rarer in nature than uranium and is more commonly used for bombs rather than as reactor fuel. Like uranium, it comes in various isotope forms, with plutonium 239 the most commonly used. It is mixed with the much more unstable plutonium 240 to generate power.
It's my understanding that a horse's knees close around age 2- 2 1/2. My gelding JUST turned 3. A couple days ago in fact. Will a horse's knees almost certainly be closed by that age?
Although infants are born with bowlegs, where the knees appear to bow out from the body, the knees tend to straighten out between 18 and 24 months of age. This means that when most children begin to walk, at around 12 months of age, they appear to be bow-legged.