但如果需要测试多个条件，例如我们假设所有条件都需要为 True 或 False (AND)，或只有一个条件需要为 True 或 False (OR)，或者如果想要检查某个条件是否不 (NOT) 符合你的条件，这时该怎么做呢？这三个函数均可以单独使用，但它们更常见于与 IF 函数成对使用。

Microsoft Defender is a security app that helps people and families stay safer online with malware protection, web protection, real-time security notifications, and security tips.Microsoft Defender is included in a Microsoft 365 Family or Personal subscription and works on your phone (Android or iOS), PC, and Mac.

The Program Install and Uninstall troubleshooter helps you automatically repair issues when you're blocked from installing or removing programs.

Website notifications appear in the lower right corner of your screen and are also displayed in the Notification Center.When notifications are turned on for a website, they will still appear even if Microsoft Edge is closed.

When you mark email as junk, you can report the message to Microsoft to help improve the accuracy of the junk email filter. To set junk email reporting options, select Settings > Mail > Automatic processing > Junk email reporting.. Specify when to send junk email reports

Sometimes you need to make a change to your email account settings. If you have a new password, if your email provider has asked you to change settings, or if you're having problems with sending and receiving email, you can change your email account settings through Mail in the Windows Control Panel, or from Outlook.

We’re continually releasing updates to our application, based on customer feedback. Check out What's New in the latest updates for Skype on desktop and mobile.

Contact Support For help with your Microsoft account and subscriptions, visit Account & Billing Help. For technical support, go to Contact Microsoft Support, enter your problem and select Get Help.If you still need help, select Contact Support to be routed to the best support option. Admins

Download and install Skype for Business on your PC. Sign in to and out of Skype for Business. Set up an audio device for Skype for Business. Set up and troubleshoot Skype for Business video

When Kelly sends an email message to anton@proseware.com, she composes it from her computer, which is identified as (i101-177.nv.litwareinc.com).The composed text is passed from her computer to the email server, mail.litwareinc.com. This is the last that Kelly will see of her email message, because further processing is handled by email servers with no intervention from her.