A:how our city Dawukou looked like
B:what our city Dawukou looked like
C:what did our city Dawukou look like
D:how did our city Dawukou look like
下列有关生态系统能量流动的叙述中,不正确的是( )
甲、乙两台机器,甲的功率比乙的大,则()