http://image.zhihuishu.com/zhs/onlineexam/ueditor/201711/3c8dfbd745244ccdaab3d1e3017187a3.png
举一反三
- http://image.zhihuishu.com/zhs/onlineexam/ueditor/201711/300f7b13d6574798b58099a680bae304.png
- http://image.zhihuishu.com/zhs/onlineexam/ueditor/201711/9d7cbc75370b44fea9e0b5d559053df8.png
- http://image.zhihuishu.com/zhs/onlineexam/ueditor/201711/167c809bec5d4089a73d82e8d5d458cb.png
- http://image.zhihuishu.com/zhs/onlineexam/ueditor/201711/8d1943673a124d34995a548554feca54.jpg
- 已知 EX=－1， DX＝3，则 ＝（ ）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201707/7bda6ce3e4e649f4885a4fd87fdae3fa.png