A:规律是客观的,违背规律必然遭到规律的惩罚
B:规律是客观的,人无法有效地应对自然灾害
C:自然界是客观的,应当限制人类改造自然
D:发挥人的主观能动性不利于环境保护
将淀粉氯化钾混合溶液装在羊皮纸制成的半透膜袋中,将此袋下半部浸泡在盛有蒸馏水的烧杯里,过一段时间后进行实验.下列现象能证明羊皮纸袋一定有破损的是( )
下列条件不能够证明a∥b的是( )
--I think it's really necessary. It is reported that the food that Chinese people
every year is enough to feed 200 million people for a year.