【简答题】阅读一下段落完成以下题目。 Three of our classmates will have their birthdays this month. To celebrate with them, we plan to buy some gifts for each of them. Jane likes music, so we are going to buy her a CD. Terry...
【判断题】外键是指一个表中含有与另外一个表的主键相同的列或列组,外键不要求唯一。
【单选题】According to the passage, which of the following is true?
A.
It is very difficult for the middle-aged to live in America.
B.
America is Kids' Country because the majority of its people are young and vigorous.
C.
Kids' Country was taking shape in America when immigrants poured into the country.
D.
America is more of Kids' Country than any other countries in the world.
【单选题】Which of the following statements is NOT true?
A.
Getting off to work with a minimum effort helps save one' s energy.
B.
Dr. Kletman explains why people reach their peaks at different hours of day.
C.
Habit helps a person adapt to his own energy cycle.
D.
Children have energy cycles, too.
【判断题】指令寄存器用来寄存当前要执行的指令地址。
【判断题】外键是指一个表中含有与另外一个表的主键相同的列或列组,外键不要求惟一
【简答题】7 某计算机有变址、间接和相对等三种寻址方式,设指令由操作码、寻址方式特征位和地址码三部分组成,且为单字长指令。设当前指令的地址码部分为001AH,正在执行的指令所在地址为1F05H,变址寄存器中的内容为23A0H,已知存储器的部分地址及相关内容如表4.1所示: 表4.1 存储器内容分配 地址 内容 001AH 23A 0H 1F 05H 2400H 1F 1FH 2500H 23A 0H 260...
【判断题】外键是指一个表中含有与另外一个表的主键相同的列或列组,外键不要求惟一。