在下列疾病中，肺的静态顺应性减少的有（）
A.肺不张
B.肺水肿
C.肥胖
D.肺气肿
E.胸廓成形术后
参考答案：A, B
已知M2O7x－+3S2－+14H+=2M3++3S↓+7H2O，则M2O7x－中M的化合价为
A．+2
B．+3
C．+4
D．+6
He _____ English for ten years by the time he takes the examination.
A．will have been studying
B．would have been studying
C．will study
D．studied
