肺栓塞最常见的咯血类型为
A.痰中带血
B.铁锈色血痰
C.黏稠暗红色血痰
D.整口鲜血痰
E.脓血痰
参考答案：D
点P（a+b，2a-b）与点Q（-2，-3）关于x轴对称，则a+b=______．
–Is Miss Green in the office? --No, she ____ to the library.
A．goes
B．had goes
C．has gone
D．would go
