QUESTION: Fix punctuation: It had colonists ensured by the just used their colonies to retrieve raw materials or allow the natives to work as slaves for them
ANS: It had colonists ensured by the just used their colonies to retrieve raw materials or allow the natives to work as slaves for them.

QUESTION: Fix punctuation: All of these texts such as the Sri Chakra Shambhala Tantra which describe how to create these mental images
ANS: All of these texts, such as the Sri Chakra Shambhala Tantra, which describe how to create these "mental images".

QUESTION: Fix punctuation: He undertook certain administrative tasks for example he was chairman of the department from 1936 to 1945
ANS: He undertook certain administrative tasks, for example he was chairman of the department from 1936 to 1945.

QUESTION: Fix punctuation: Electricity is mainly produced inside the EU based on a wide range of sources and technologies
ANS:
Electricity is mainly produced inside the EU, based on a wide range of sources and technologies.