(2015•河南)下列各项中,属于我国《环境空气质量标准》基本监控项目的是( )
A:SO2浓度
B:O2浓度
C:N2浓度
D:H2O浓度
Linda needn't________her parents any more—she could be entirely independent by working as a nurse.
如图,①~④表示某细胞内部分细胞器。下列有关叙述正确的是( )
It won't be long ______ you regret what you have done.