A:(kπ﹣ 14 ,kπ+ 34 ,),k∈z
B:(2kπ﹣ 14 ,2kπ+ 34 ),k∈z
C:(k﹣ 14 ,k+ 34 ),k∈z
D:( 2k−14 ,2k+ 34 ),k∈z
Over years,scientists have made a great________in the treatment of cancer.
一块体积为0.7米3的石块质量是1820千克,在国际单位制中,这块石块的密度是____千克/米3.它的单位读作____.