Answer:
6)j
L. my grandmother is washing the dishes, my sisters are watching TV and I am playing chess....
J. I am sure you are having a great time with your grandfather! I am trying to solve a difficult math problem.....
L. My parents are coming to get us....
7)
1. It is raining at the moment.
2. I am wearing my new trousers right now.
3. You are doing a grammar exercise at the moment.
4. Emma is buying flowers for her mum now.
5. Our teacher is grading our tests at the moment.
6. The children are swimming in the pool right now.