he process we have developed is based exclusively on renewable energy sources_______(52)thermal solar collectors and photovoltaic ceils，_________(53)makes this methodcompletely energy-autonomous．It will_______(54)function in regions where there is no electricalinfrastructure．"says Siegfried Egner，head of the research team．The principle of the_______ (55)is as follows：hygroscopic brine-saline solution which absorbs moistureruns down a tower-shapedunit and absorbs water from the air．It is then sucked_________(56)a tank a few meters off the ground in which a vacuum prevails．Energy from solar collectors_________(57)up the brine，whichis diluted by the water it has________(58).

　　Because of the vacuum，the boiling point of the liquid is lower thaa it would be under_____ (59)atmospheric pressure．This effect is known from the mountains：as the atmospheric pressure there is lower than in the valley，water boils at temperatures distinctly below 100~C．The evaporated， non-saline water is condensed and runs down through a completely filled tube in a controlled manner．The gravity of this water column_________(60)produces the vacuum and so a vacuum pump is not needed.The reconcentrated brine________(61)down the tower surface again to absorb moisture from the air．

　　"The concept is suitable for various water_________(62)．Single-person units and plants supplying water to entire hotels are conceivable，"says Egner．Prototypes have been built for______

　　(63)system components-air moisture absorption and vacuum evaporation-and the research scientistshave Mready________(64)their interplay on a laboratory scale．In a further________(65)the researchers intend to develop a demonstration facility．

　　51．A．road B．channel C．way D．path

　　52．A．in spite of B．because of C．as a result of D．such as

　　53．A．who B．where C．when D．which

　　54．A．meanwhile B．therefore C．however D．still

　　55．A．prospect B．process C．progress D．product