A:not allowing
B:not being allowed
C:not allowed
D:having not being allowed
湖泊生态系统中的草食鱼以水草为食,属于消费者;肉食鱼以草食鱼为食,应属于:
考古人员在北京人遗址中发现了大量木炭和几处较大的灰烬堆,这说明北京人( )
There _______ three green bags in the room. ( )