What is the time limit for responding to patent examination opinions?

According to the Patent Examination Guide 20 10 (Revised Edition), the reply period of the first notice of examination opinions in the preliminary examination stage is 4 months, and the reply period of the notice of re-examination opinions is 2 months. If the applicant fails to reply to the notice of examination opinions within the time limit without justifiable reasons, his application shall be deemed to have been withdrawn. If the applicant or agent thinks it is difficult to reply within the time limit specified in the notice, he may submit a written request for extension before the expiration of the time limit for reply and pay the extension request fee before the expiration of the above time limit.