重庆谈判中，蒋介石始终不承认人民军队和解放区的合法地位，其根本目的是[      ]

A．不承认中共的合法地位

B．为发动内战做准备

C．降低中共的威信和地位

D．实现独裁政治

They all go outing on such a warm spring day（）Mark. He is busy with his lessons now.

A.beside   

B.besides   

C.except for

D.except