把x=-1代入原方程，得：2-1+3=m-1+2，解得m=1．
词汇运用。根据汉语释义，写出词或短语的正确形式。
1. I'm used to _____ (处理) matters of this sort.
2. The Fashion Show will _____ (举行) from 12th to 20th May.
3. Look! The dogs are looking for food _____ (careful) in the street.
4. The film star has been _____ (死亡) for years.
5. I believe you have made a good _____ (决定).
秦朝确立了专制主义中央集权制度，适应了（）①维护国家统一的需要②自然经济存在的需要③保护地主土地制度的需要④推动多民族国家发展的需要
A.①②③
B.②③④
C.①③④
D.①②③④
