MCTS70-515 question on ajax library?

You are implementing an ASP>NET application that makes extensive use of javscript libraries. Not all pages use all scripts, and some scripts depend on other scripts. When these libraries load sequentially, some of your pages load too slowly. You need to use the ASP>NET Ajax Library script Loader to load these scripts in parallel. Which two actions should you perform?(Each correct answer presents part of the solution. Choose two)

1. In your site's master page, add a call to Sys.loader.definescripts to define each of the scripts that are used in the site.

2. In your site's master page, add a call to Sys.loader.registerscript to define each of the scripts that are used in the site.

3. In each page that uses scripts, add a call to Sys.get for each script th开发者_如何学Cat is needed in that page.

4. In each page that uses scripts, add a call to Sys.require for each script that is needed in that page.

Please tell me which are the two answers are correct and why?

Thanks

1 and 4, because that's what http://weblogs.asp.net/bleroy/archive/2009/11/23/enabling-the-asp-net-ajax-script-loader-for-your-own-scripts.aspx and http://www.asp.net/ajaxlibrary/HOW%20TO%20Load%20Required%20Scripts.ashx imply.