设有 s(学号,姓名,性别)和 sc(学号,课程号,成绩)两个表，下面 SQL 的 SELECT 语句检 索选修的每门课程的成绩都高于或等于 85 分的学生的学号、姓名和性别。SELECT 学号,姓名,性别 FROM sWHERE _________(SELECT * FROM sc WHERE sc.学号=s.学号 AND 成绩<85)
查看答案
以太网是采用总线结构的一种局域网。在以太网中，所有的结点(计算机或其他设备)通过以太网卡和电缆连接到一条总线上，并采用 【17】 方式进行相互间的数据通信。
Why was postage high in the early 19th century
A. [A] Because the prices of goods (物价) were very high.
Because the post office wanted to earn too much money.
C. Because many people had to be paid for getting the postage.
What can we learn from the dialogue
A. [A] The man is going to repair the tape-recorder.
B. The tape-recorder is stolen.
C. The man is going to find the tape-recorder.
计算机的主存储器(内存)用来存储数据和指令，为了实现按地址访问，每个存储单元必须有一个唯一的地址。PC机主存储器的编址最小单位是 【4】 。
微信支付 
支付宝支付