A:CO和N2
B:N2H4和C2H4
C:O3和SO2
D:CO2和N2O
从上层建筑领域给贵族政治以沉重打击的梭伦改革的措施有( )
①鼓励发展工商业 ②确立财产等级制度
③设立四百人会议 ④成立公民陪审法庭
—Where is my music disc? I can't see it!—You'd better________ the disk carefully in your bedroom.
-- How are you?
-- I'm .
如图所示,袋鼠妈妈把小袋鼠放进育儿袋中后,在草地上向前跃进。说小袋鼠是静止的,选取的参照物是( )