两个桶里共盛水40斤，若把第一桶里的水倒7斤到第2个桶里，两个桶里的水就一样多，则第一桶有（ ）斤水。
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Many useful tools and techniques are used in developing schedule. ______ is a schedule network analysis technique that modifies the project schedule to account for limited resource.
A．PERT
B．Resource levelling
C．Schedule compression
D．Critical chain method
C.NG是（）的英语缩写。
