Good luck for your exam and do your best. 祝你考试顺利,加油。 You can do this. Best of luck. 你一定行的/加油。 It’s your lucky day. 这是你的幸运日。 I wish you success in/with your exams. 祝你考试顺利/考出好成绩。 祝福考生朋友们一切顺利!