Tim is in good shape physically _____ he doesn't get much exercise.[ ]

A. if

B. even though

C. unless

D. as long as

税收预测就是以充分掌握影响税收收入变动的因素和（）为基础，以统计方法、数学方法为手段。

A.税收历史资料

B.税收现实资料

C.理论数据

D.预期目标