51.A.lead B.compare C.add D.owe
50.A.as to B.thanks to C.but for D.in spite of
49.A.rare B.ordinary C.popular D.modern
48.A.with B.of C.by D.in
47.A.published B.did C.discovered D.created
46.A.use B.origin C.expression D.meaning
45.A.software B.hardware C.speaker D.operator
44.A.Unfortunately B.Ironically C.Luckily D.Suddenly
43.A.plenty of B.lots of C.sort of D.lots of
42.A.deeply B.widely C.seldom D.hardly