One word is missing in each sentence. What is it?

1. It seems me that there is a problem. seems to
2. One of the advantages studying law is that it should lead to a good career. 
3. It is important to give sides of the argument. 
4. Too much time spent in front of a television can have a bad effect children. 
5. People like to have freedom of choice. On the other, too much choice can be a bad thing. 
6. Time tends go faster as you get older.