According to the provisions of the Review Guide, the reply period of the first review notice is four months, and the reply period of the second review notice is two months. Please pay attention to the reply period and ensure that the reply is submitted within the specified time limit. If the inventor thinks that it is really difficult to reply within the time limit specified in the notice, he may submit a written request to extend the time limit before the expiration date of the reply period 15, requesting the Patent Office to extend the specified reply period.