下列何者是0.000 815的科学记号( )
A.8.15×10-3
B.8.15×10-4
C.815×10-3
D.815×10-6
0.000 815=8.15×10-4.故选B.
商品经济产生和存在的决定条件是( )
A.社会分工
B.机器的出现
C.生产资料和产品属于不同所有者
D.货币的使用
Man: Look, the view is fantastic.Could you take a picture of me with the lake in the background Woman: I'm afraid I just ran out of film. Question: What do we learn from the conversation
A.The woman is watching an exciting film with the man.
B.The woman can't take a photo of the man.
C.The woman is running toward the lake.
D.The woman is filming the lake.