In a medical malpractice action, plaintiff appeals from an order of the Supreme Court, Nassau County (Meade, J.), dated April 24, 1981, which, inter alia, denied his motion to strike certain interrogatories. Order affirmed, with $50 costs and disbursements. Plaintiff's time to answer is extended until 20 days after service upon him of a copy of the order to be made hereon, with notice of entry. Plaintiff failed to object to the interrogatories within the time limit set forth in CPLR 3133 (subd [a]). (See Newark-Wayne Community Hosp. v. Cleaver-Books, Inc., 59 A.D.2d 821.) In any event, plaintiff failed to sustain his burden of proof on the question of whether the information requested required the disclosure of expert testimony, attorney's work product, or material prepared for litigation. (See Koump v Smith, 25 N.Y.2d 287; Stengel v. Long Is. Light. Co., 61 A.D.2d 838.) Accordingly, we affirm the order appealed from. Lazer, J.P., Mangano, Gibbons and Gulotta, JJ., concur.