【题目】The dog may be a good companion for the old. _______, the need to take it for walks may be a disadvantage.
A.Besides.
B.However
C.Therefore
D.Instead

【答案】B
【解析】句意：狗也许是老年人的好陪伴，然而需要带着狗去散步时也许有不便。前一句话有good，后面一句话有disadvantage，前后两句话有转折关系，所以选择however。