下列哪种疾病可出现肺血减少的X线征象是()
A.室间隔缺损
B.风湿性心脏病二尖瓣狭窄
C.原发性肺动脉高压
D.高血压性心脏病
E.以上都不是
参考答案:C
It’s hard-working ____ him to spend three hours ____ the library on Sunday.
A.for; in
B.for; on
C.of; in
D.of; on
新疆鸟类中猛禽居全国首位的有()种
A、40
B、46
C、50