题目

If you think a Web site designed especially for complaining sounds unique, then think again. If you have a complaint, there are hundreds of sites that allow you to get it off your chest. Sites exist for complaining about such things as defective products, government inefficiency, and offensive advertising. There are even sites where you can complain about anything that bugs you, including love, family, or just the weather. These Web sites won’t actually do anything about your problem; they just let you blow off steam. Here’s a sampling of complaints people have written:1. Something I can如图，在△ABC中，BC=2，则中位线DE=    ．