—How much did you spend on your new iphone?
—About 7000 yuan.
A:take
B:cost
C:pay for
你最喜欢听的名曲是什么?出自谁的作品?
(Ⅰ)求P;
(Ⅱ)证明:当m,n∈P时,|mn+4|>2|m+n|.
李亮同学在实验室里发现一张脱落标签的永久装片,他借助显微镜观察到如图所示的图象,该装片属于( )