Q9-8.
c
Answer
Explanation
A key that specifies a record in a table is called a primary key. Student numbers are assigned
to each student. These numbers are unique, making them appropriate for use as primary keys.
Q9-9.
c
Answer
Explanation
The member number of the female whose current address and work location are both in Tokyo is “0004.”
Q9-10.
c
Answer
Explanation
The following items have a sales price of 50,000 yen or more: large refrigerator, medium refrigerator, small refrigerator, air purifier, and air conditioner. Of this list, items with an inventory of less than 10 units are the medium refrigerator, small refrigerator, and air conditioner.
Q9-11.
b
Answer
Explanation
When multiple persons concurrently write to a file, only the changes made by the last person
are kept. There is a chance that the previous changes will be lost.
Q9-12.
b
Answer
Explanation
A LAN is a network for exchanging information within a relatively confined area such as
within a single building, site, plant, or school.
Q9-13.
d
Answer
Explanation
A protocol is a set of rules determined for data communications between computers over a
network.
Q9-14.
b
Answer
Explanation
A URL is used to specify the location of information sources (resources) on the Internet. The
URL specifies the protocol for receiving a Web page, and is written using a specific format
that indicates the host name and domain name of the Web page.
17