测定水分可用干燥法，包括直接干燥法和（）。
参考答案：减压干燥法
The successful launch of Tiangong1 symbolizes a further step for China to join in the________of space stations previously mastered by Russia and the US.
A．invention
B．production
C．operation
D．preparation
挖掘机的工作部分由哪些部件组成？
