Group items tagged

Tags help you find and organize your bookmarks by letting you select all of your bookmarks with a certain tag or combination of tags. Quickly add relevant tags to a bookmark by clicking on any of the recommended tags that appear under the description field on the “Save Bookmark” pop-up. When you are satisfied with the information in the “Save Bookmark” pop-up, click the “Save Bookmark” button. Now a link to the page is stored in your Diigo library, and the information you entered is stored with it.

Highlight Highlighting lets you denote important information on a page, just like highlighting in a book, but with Diigo, the highlighted text will be conveniently saved to your library as well. There are some important things for me to denote on my recipe. My wife doesn’t like pineapple, my grandfather can’t have eggs or chocolate, and I don’t like coconut very much, so I highlight those items on the recipe to let me know I need to deal with them. Highlight by clicking “Highlight” on the Diigolet. Then select the text you want to highlight. The text will be visually highlighted and the text is now stored in your library. It’s that easy. Click the button again to exit highlighter mode. You can also change the color of a highlight by clicking the downward-pointing arrow next to “Highlight” and choosing a color. Colors are useful for differentiating different types of highlights. I will use a different color for each of the different people I need to consider.

To add a sticky note to a highlight, simply move your mouse cursor over a highlight. When the little pop-up tab with the pencil on it appears, move the cursor to it and a menu will appear. Choose “Add Sticky Notes”. Now you can type and post a sticky note just like before, but this time it will be tied to the highlighted text.

再加上宋太祖赵匡胤严格防范地方将领拥兵割据，采取 “强干弱枝，内外相制” 的军事策略，即将天下兵马的一半驻扎在首都，另一半分散到全国各地，而且厢军（地方军队）的战斗力比禁军更拉胯。这样做的后果是，北宋地方兵力空虚，导致其在与周边民族政权的战争中多处于劣势。

而洛阳位于开封西面 170 多公里。水路需要经过黄河，此时的黄河航运条件并不理想，因此在接收江南运来的物资方面，并没有开封便利。再加上洛阳屡次经历战争破坏，远不如开封繁华富庶。

试图迁都，直接碰壁尽管赵匡胤在夺位后选择定都于此，但他本人对开封并不满意，一直想要迁都到洛阳去，并以此为跳板，最终迁至长安。一方面，多个重要朝代定都于此，沿袭旧制可 “彰显” 自己的正统地位。另一方面，古代王朝选择都城，必定要考虑安全因素，如古都长安，被关中四塞（东函谷关，后为潼关，西大散关，南武关，北萧关）所拱卫，又有秦岭、崤山凭依，攻取难度颇大。而洛阳则背依北邙山，有伊、洛、瀍、涧四水，东有让李世民一战擒双王的虎牢关，西有潼关作为门户，同样难以攻取。长安和洛阳其实都位于盆地中长安是关中盆地，洛阳是伊洛盆地军事上的安全性有余，但经济资源已严重不足