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).
To obtain the benefit of the provisional filing date, a non-provisional patent application must be filed, claiming benefit of the filing date of one or more specific provisional patent applications, prior to their expiration. The provisional patent application is only pending for 12 months prior to becoming abandoned.he provisional filing date is not counted as part of the 20-year life of any patent that may issue with a claim to the provisional filing date. The United States Patent and Trademark Office (USPTO) announced on December 8, 2010, that it was implementing a Missing Parts Pilot Program.