沿河分布是中南半岛城市分布的主要特征之一，其中老挝首都万象就分布在（    ）

Dear Jenny,
   Please take these things to your brother: his math book, baseball, notebook, CDs, and video tape. The math book is on the dresser. The baseball is under the bed. The notebook is on the bed. The CDs are in the drawer. The video tape is on the table. Thanks!
                                                                                                                                                                            Mom

（1）先化简，再求值：（2a²﹣5a）﹣2（3a﹣5+a²）．其中a=﹣1；
（2）若|m|=4，|n|=3，且知m＜n，求代数式m²+2mn+n²的值．