三種執行我們教學的方式：

	Use the PhET website while connected to the web	Download the entire website onto your computer, USB, or CD	Download one or more simulations to your computer, USB, or CD

How do I get the simulations?	Click on the simulation icon on the web page of the simulation you want to run.	Click here to go to the download page.	Click here to go to the all-simulations download page.
What simulations are installed?	The simulations you use are temporarily installed.	All simulations.	Only the ones you want.
How large is the download?	Under 1.5 MB for each simulation.	Approximately 40MB if you already have Java, or 65MB if you do not.	Under 1.5 MB for each simulation.
How often are updates made available?	As soon as new or updated simulations are posted on the web site.	Three or four times a year.	If you connect to the Internet, new or updated simulations are available.
Is an Internet connection required to run simulations?	Yes	No	No
Where can I save them to on my computer?	Flash applets cannot be saved. Java applications are automatically stored in your computer's WebStart cache, but cannot be moved.	CD, USB or hard drive.	CD, USB or hard drive.