Instructions: Use the pull-down menu box to select the best alternative. When you choose a correct passive, the exercise will explain why it is correct. This feedback is important. It explains the reasons why certain answers are incorrect, so make sure you read the explanations, too!

Comments to the teacher: If you experience any problems, or have questions or comments about this exercise, please click on the icon in the left-hand corner at any time during the exercise to send an automated email message to your teacher.

Estimated time: 15 minutes.