急性硬膜外血肿最常见的出血来源为()
A．颅骨板障
B．静脉窦
C．脑膜中动脉
D．大脑中动脉
参考答案：C
浇注系统中，扩大横浇道的断面积，可加强其挡渣能力。
Lincoln, who many regard as one of our great presidents, was often ______ despite his reputation of telling good jokes.
A．bright
B．optimistic
C．gloomy
D．cheerful
