The fact that historians have done harm by distorting truth, means that people believe what is reported by the historians. So, I is implicit. II does not follow from the statement and so is not implicit.
7. Statement: "As there is a great demand, every person seeking tickets of the programme will be given only five tickets."
Assumptions:
The organizers are not keen on selling the tickets.
No one is interested in getting more than five tickets.
Clearly, the organisers are adopting this policy not to reduce the sale but to cope up with great demand so that everyone can get the ticket. So, I is not implicit. Also, due to great demand, the maximum number of tickets one person can get has been reduced to five. So, II is also not implicit.
8. Statement: "Computer education should start at schools itself."
Clearly, computer education can be started at the school level only if it is easy. So, I is implicit. In the statement, nothing is mentioned about the link between jobs and computer education. So, II is not implicit.
9. Statement: If he is intelligent, he will pass the examination.
The statement mentions that he will pass if he is intelligent. So, I is implicit. Further, this means that it is not necessary that he will pass. So, II is not implicit.
10. Statement: Today I must satisfy myself only by looking at a pink headed duck in an encyclopaedia.
Assumptions:
Pink headed ducks are as good as extinct now.
People refer to encyclopaedia to know only about things which do not exist now.
Since the narrator talks of satisfying himself by just looking at a picture in encyclopaedia, it means that pink headed ducks are not to be seen alive. So, I is implicit. But II does not follow from the statement and is not implicit.