Title: אופציונלי

Text: The comparison between the wave theories of sound and light was so productive that scientists spent a great deal of effort looking for a medium that would propagate light the way air propagates sound. They even gave it a name, "ether," but they never found the medium. The analogy that had been so fruitful in some ways proved to be misleading in this case. כל פסקה תהיה מבחן.

Save test: השתמש בזה אם אתה רוצה לשתף את המבחן הזה בהקלדה (רק למשתמשים מאומתים).