You should try to get a good night’s sleep ________ much work you have to do．

A.however

B.no matter

C.although

D.whatever

答案及解析： A

解析：

此题考查连词的用法。据题干内容，主从句存在着让步关系，最佳选项应为A项。however much work＝no matter how much work表示“无论多少工作”。