阑尾炎时，阑尾穿孔是因为()
A．血运障碍
B．细菌入侵
C．管腔梗阻合并管壁坏死
D．淋巴组织坏死
E．管壁肌肉收缩
参考答案：C
_____ the right decisions _____ the future is probably the most important thing we'll ever do in our lives. [ ]
A. Making; concerned
B. Make; concerning
C. To make; concerned
D. Making; concerning
论述最佳点火提前角是如何计算的？
