This shirt nice I will take it. [ ]
A. is
B. am
C. are
答案：A
继发性红细胞增多症是( )
A．血容量减少B．白细胞减少C．血小板减少D．动脉血氧饱和度减低E．红细胞生成素减低
The acids in acid rain are the only reason that forms urban smog alone.
