Basically the issue with the knees is you don't want to start riding a horse too strenuously until the knees close. For each breed it is different. Some close at 3, others, like drafts and WBs, can wait until 5 or so.
the act of making or enacting laws. 2. a law or a body of laws enacted. Origin of legislation.
A bill is proposed legislation under consideration by a legislature. A bill does not become law until it is passed by the legislature and, in most cases, approved by the executive. Once a bill has been enacted into law, it is called an Act or a statute. 1 Usage.