单项选择题 After you install a new updsate, an application on the computer fails to run. You need to remove the update. What should you do?（）

单项选择题 Your portable computer has two 512-MB memory modules installed in the only two memory slots available. You need to improve the speed of your computer. What should you do?（）

单项选择题 You delete content from a file named Speed.doc that is stored in the C:\Data folder. You edit 20 files in this folder over the next two days. You need to restore the version of the file that had the correct data. You also need to ensure that the other fiels in the folder remain unaffected. What should you do?（）