三度房室阻滞（）
A.PR间期延长、P与QRS关系固定
B.PR间期逐渐延长，有QRS脱漏
C.前者均有
D.两者均无
参考答案：D
The ____ expression on his face suggested that he ____ understand what I said.
A．puzzling, should not
B．puzzled, did not
C．puzzle, was not
D．puzzled, not
卵巢主要功能为_____及_____两部分。
