Why do sewer rats grow so much larger then pet rats do? Are they a different species and if so how come they do not make it into the pet trade as in captive bred clean versions? I saw a rat as big as two large cats within one the other day and this got me to thinking, hence the question above.
In the United States, under current patent law, the term of patent, provided that maintenance fees are paid on time, are: 1  For applications filed on or after June 8, 1995, the patent term is 20 years from the filing date of the earliest U.S. or international (PCT) application to which priority is claimed (excluding provisional applications).
How long a patent lasts depends on the type of patent being issued and the country issuing the patent. For example, under recent changes in the laws, in the United States, patents are now granted for a term of 20 years from the date of application (14 years for design patents).Different rules apply for patents from applications filed before June 8, 1995.or example, under recent changes in the laws, in the United States, patents are now granted for a term of 20 years from the date of application (14 years for design patents). Different rules apply for patents from applications filed before June 8, 1995.