21．― Excuse me, where can I get _____ application form?
― Go to _____ Window 10 ,please.
A．an;不填 B．an; the C．不填；不填 D．the; the
22．What the scientist said sounded strange, ______ ,they made sense.
A．therefore B．however C．since D．otherwise
23．Napoleon would have taken over the world if he ______ the Battle of Waterloo．
A．wins B．won C．had won D．has won
