The manufacture of rubber breathing pipes made it possible for divers______on the surface of the water.
A．float
B．floating
C．to float
D．to be floated

未分类题Counting will not begin______tomorrow______the result will be announced.A．yet, andB．yet, butC．until, butD．until, and

未分类题The proportion of elderly people in the population is steadily growing______ they live longer; ______that fact brings them ever worsening problems.A．while, soB．when, butC．as, whilstD．whilst, just

未分类题Whatever difficulties we______with, well go on with the experiment.A．might meetB．will meetC．would have metD．should have meet

未分类题We use very little energy to maintain a fat store, _____a protein store needs a lot.A．whereasB．in contrast toC．on the other handD．since

未分类题Ive no idea when shell be back. ______you wait or come back later is up to you.A．WhenB．IfC．WhetherD．That