某工程双代号网络计划如下图所示,其关键线路有()条。
A.2
B.3
C.4
D.5
参考答案:C
解析:
对于双代号网络计划可采用标号法快速确定关键线路和计算工期,计算结果如下图所示。
铸钢件易产生缩松、缩孔,因此大多数铸钢件采用同时凝固设置浇注系统。
This vehicle bounces and glides along the ground ().
A. at an average speed of 40 miles an hour
B. of 40 miles an hour at an average speed
C. at 40 miles an hour of an average speed
D. of an average speed at 40 miles an hour