First or second conditional?

1.Anna told me to leave her a note before I started for Moscow
2. It asked him if he had had any difficulty in solving the problem
3.Martin told us that he was busy that week. He wanted us to ring him up the following week
4.The teacher told us that we could go home then,because the lessons were over.
5.Peter told his friend not to keep him wait for him long
6.The farmer told his son that it was getting colder and soon it might snow
7.The gardener asked us to help to pick the apples
8.The man said that it had been very dark the night before
9.The teacher asked us what we didn't understand,

In my opinion, there are good and bad sides in it. On one hand, many people can find some good and helpful information about something they're interested in. So, that's why, we can use it to learn lots of interesting facts and articles. On the other hand, we sit in front of the computer for a long time and it can be a reason of degradation musculoskeletal system and spoiled eyesight. That's really dangerous for our health. There are some inadequate and little people in the Internet. They can find harmful things there. But I don't agree with it, as one can control his being in front of the computer and limit access to some sites. But disputes will continue and only time can show us different results.