Hi to all my hardworking FR9 students. I couldn't invite you to the blog yesterday evening because of technical problems. But by now you should have received an invite to the blog in your gmail account. Please accept and then post on the blog. Thank you all very much for your patience :).......And here is a little puzzle for you to solve for next lesson:

'How can you throw a ball as hard as you can and have it come back to you, even if it doesn't bounce off anything? There is nothing attached to it, and no one else catches or throws it back to you.'