Database Administration Questions

We know a proverb that An apple a day keeps the doctor away. To keep the doctor away from her, he gave seven apples, each apple a day.

Permanent hardness of water may be removed by the addition of Sodium Carbonate.

Economic resources include land, labour, capital and entrepreneurship. 

Entrepreneurship is also considered an economic resource because individuals are responsible for creating businesses and moving economic resources in the business environment.

These economic resources are also called as Factors of production.

A Telephone or an Alarm...

IPv6 - Internet Protocol Version 6.

IPv6 addresses have a size of 128 bits.

Internet Protocol Version 6 [IPv6] is the successor to the Internet's first addressing infrastructure, Internet Protocol version 4 (IPv4).

In contrast to IPv4, which defined an IP address as a 32-bit value, IPv6 address have a size of 128 bits. 

The second would employ a comma, or semi-colon, and not a colon so it is not properly punctuated.

The third sentence would not be correct because it uses 'like', usually used for comparison. Since you are not comparing two questions, it would not be appropriate.

The fourth sentence has 'is' before the colon, which is a implies declaration and not listing. So, again, it would not be appropriate.

Hence, the first sentence, however, is punctuated correctly.