Переведите предложения, обращая внимание на функции и значение слов it и

Переведите предложения, обращая внимание на функции и значение слов it и one.
1. It is not easy to investigate a criminal case.
2. As the trial was open to the public many people attended it.
3. It was the Prison Act (1865) which introduced a new approach to imprisonment in England.
4. A written constitution is one the whole of which is contained in one or more documents which possess the force of law.
5. One must observe traffic rules.