Mary is from England, but _____ friend Jim isn't English. [ ]
A. she
B. her
C. he
D. his
答案:B
胸膜腔内压的负值大小取决于()
A.肺内压与胸膜腔内压之差
B.肺内压与大气压之差
C.肺回缩力
D.呼吸肌的舒缩
E.大气压与肺回缩力之差
变压器的扇形温度计是反映变压器()的。
A.绕组温度
B.铁芯温度
C.上层油温
D.下层油温