对妊高征病人,下列症状中,哪项不属于先兆子痫().
A.头晕
B.呕吐
C.胸闷
D.视力模糊
E.头痛
参考答案:C
He _____ football regularly for many years when he was young.
A.was playing
B.has played
C.played
D.had played
什么叫内力?什么叫应力?什么叫强度?