How did the policies of ruling governments policies prevent colonies from developing their own economies?

The colonies cannot manufacture their own goods and cannot enter into trade deals with other nations.

Explanation:

The following are the factors for which the policies of the ruling governments prevented their colonies from developing their own economies are  :

1. The colonies are forced to sell their raw materials for the various products to the parent countries.

2. They also have to buy the manufactured goods from the parents countries.

3. They cannot manufacture their own products and goods.

4. There are various laws that imposed strict restrictions to the creation of any local industries and also prevented them from entering into any trade deals with other countries.

it's not the readmission

in his book, the riddle of the rosetta stone, james giblin talks about how there was a young british polymath and physician named thomas young who made a lot of advances on the deciphering of the rosetta stone. he says that even though young made a lot of mistakes because he was working under false assumptions, he also made huge contributions like deciphering three out of the seven symbols (more than anyone else before him). young published his findings and continued his good work but he wasn't able to progress much further due to some unfavorable situations, he still laid the basis for many other scholars and of course for the man who has been generally known to have deciphered it, jean-françois champollion