Topic Sentences

hello everyone
I have these questions that I do not understand well in my school book , but I really did it I just need someone to check the answers for me .. will you help me pleas ?
* study the topic sentences that follow. Circle the contolling idea and underline the topic in each sentences. Note they might expressed in more than on word :
1. A final advantage Martina Navratilova had on the court was her costant aggressiveness.
2. A properly planned science fiction course should include a unit on political implications.
3. Einstein's unsuccessful attempt to get unclear weapons banned was dissappointing .

* I wrote these topic sentences , what do you think of them ?
My hometown is safe and secure.
A Few chairs at this school one of many improvements are needed.
Exercise is good for your heart health.
Talking on the phone while driving can be hazardous.
Typing on a computer keyboard is convenient.
Smelling the roses is interesting to do at the park.
Watching a lot of television is bad for children.