1、南海资源丰富,其面积约为350万平方千米,相当于我国的渤海、黄海和东海总面积的3倍,其中350万用科学计数法表示 为··················(    )
A、        B、       C、       D、
2、在 ,0,- , , , ,0.3030030003, 中,无理数有·····························································(    )
A、2个       B、3个      C、4个          D、5个
3、估计- 的值在···········································(    )
A、-2至-1之间               B、-3至-2之间
C、-4至-3之间               D、-5至-4之间