Go to the Macmillan Secondary Course web site, introduce your password and do these exercises:
Present Simple + Present Continuous 1
Present Simple + Present Continuous 2
Subject-Object Questions 1
Subject-Object Questions 2
Helping Good Causes
Remember that you can use your book if you have any problems with the exercises. I'm sure you will find similar exercises there.
I will check your work on Wednesday, Oct 20th, 2010.