Answer:
1. You can switch off the TV. Not watch this programme.
2. Call me later! I am doing our Maths homework right now.
3. Usually, we do not watch a lot of TV but we are watching a really exciting film at the moment.
4. They usually go to school by bus but today they are walking.
Present Simple:
Формула: V( +s)
Present Continuous:
Формула: am/ is/ are+ Ving