Medium speed engines have a () power to weight ratio than the slow speed two strokes, but due to the higher speeds tend to have () maintenance intervals.
A. higher;reduced
B. higher;increased
C. lower;reduced
D. lower;increased
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患者女性,50岁,临床以黄疸就诊,CT显示胆囊增大,内有结石,胆总管扩张,在胰头段略细而突然中断,增强扫描见胆总管下段壁明显增厚且有强化,应考虑为:()
A. 急性胆囊炎
B. 慢性胆囊炎
C. 硬化性胆管炎
D. 胆总管下段癌
E. 以上都不是
通常所确定的缺陷大小,就是所检测的实际缺陷的大小。
A. 正确
B. 错误