You can only unlock the chapter using a special code that we will send you via the Viber app. Receiving a message is free of charge and with no obligations.
My phone number:
Get a code
In compliance with the law, persons under the age of 15 can enter their phone number only in the presence of a parent or guardian.
4-character code:
Check the received code
The page will be refreshed automatically in a few seconds.
The reason why it is necessary to take precautions when using X-rays is to prevent health hazards which include skin burns, cancer, destruction of body cells, genetic mutations with undesirable hereditary consequences, body tissues, and Leukaemia.
To view the solution, you need to log in.
You must confirm your username (email address) to view the solution.
To ensure the proper functioning of the website, OpenProf uses cookies that do not store personal data. By continuing to use the website, you agree to cookies. Tell me more »
