As used in this passage,the word “valid” in the second paragraph means______
A. foreign
B. 1egal
C. monetary
D. illegal
第1题:
In a flash type evaporator, all saltwater heaters are vented through individual vent cocks to the ______.
A.saltwater heater shell
B.second-stage condenser
C.atmosphere
D.second-stage flash chamber
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