(2013·大连24中模拟)Good health is the basis for students to ________ carry on with their studies and to do any other activity.

A．especially

B．dependently

C．effectively

D．reasonably

A：条件(1)充分，但条件(2)不充分．
B：条件(2)充分，但条件(1)不充分．
C：条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
D：条件(1)充分，条件(2)也充分．
E：条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．

|2x+a|+|2x-b|＜6在实数解集上非空．
(1)(3a-26)²+|ab-6|=0；(2)M(a，b)为圆x²+y²=9内一点．