肺心病继发性红细胞增多是因为（）．
A.血液黏度增加
B.急性缺氧
C.慢性缺氧
D.血流阻力增加
E.肺动脉高压
参考答案：C
---What did the old man say?
---Oh, he told us _________ football in the busy street.
A．don’t play
B．not to play
C．not playing
D．wouldn’t play
个人所有的房产，除出租者外，一律免征房产税。 ( )
