A:依赖性
B:自制型
C:自主性
D:冲动性
Steve's activity on Sunday
In the past
He spent most of the time 1.
He learnt it from his 2 and he is good at it.
Now
He spends at least 3 hours collecting rubbish.
He would like to protect the beach.
细菌、真菌分解自然界中的有机物,产生的物质是( )