物联网按照应用领域分，不存在（）。
A.医学物联网
B.建筑物联网
C.环境物联网
D.社会物联网
参考答案：D
— Do you think I should go to the seaside for a rest?
----______ . You have been busy for such a long time.
A．It depends.
B．It’s up to you.
C．Why not?
D．What about you?
Photoshop中只能用拖移的方法来改变图层的前后顺序，没有其他操作方法。
