业余无线电台执照有效期届满后需要继续使用的，应当在什么期限内向核发执照的无线电管理机构申请办理延续手续？
参考答案：
有效期届满一个月前
患者男性，30岁，主诉口渴、多饮、多尿1个月，空腹尿比重偏低。
为确诊此病人有无尿崩症，下列试验首选()
A．禁水试验
B．测每日尿量
C．禁水-加压素联合试验
D．测血浆渗透性
E．测尿渗透压
Directions: For this part, you are allowed thirty minutes to write a letter. Suppose you are Zhang Ying. Write a letter to Xiao Wang, a schoolmate of yours who is going to visit you during the week-long holiday. You should write a t least 100 words according to the suggestions given below in Chinese.1.表示欢迎2.提出对度假安排的建议3.提醒应注意的事项
