43.Both sides agree to establish a _______ zone between the south and north. (来源：老牌的英语学习网站 http://www.EnglishCN.com)

A. midst B.mild C.mention D.neutral

44.This is a _______ moment for our research. We should be careful.

A. critical B.belt C.conscience D.copper

45.This textbook is for the _______ students, not for the beginners.

A. observation B.transportation C.advanced D.transfer

46.When I read the newspaper, I always read the _______ first.

A. headlines B.headquarters C.heaven D.horizon

47.They _______ our house at $10,000.

A. count B.vanish C.weave D.assess

48.When he studied at college, Jack was supported by a _______.

A. treatment B.assistance C.scholarship D.protein

49.Even as _______, he made several wonderful inventions.

A.a stock B.a representative C.an undergraduate D.a gulf

50.An emergency _______ is very important in case of fire.

A. exit B.deposit C.discharge D.elaborate

答案:
1.A 2.B 3.C 4.A 5.B 6.C 7.A 8.C 9.D 10.A 11.A 12.A 13.B 14.D 15.A 16.B 17.D 18.D 19.A 20.C 21.D 22.D 23.A 24.A 25.B 26.C 27.A 28.A 29.D 30.A 31.B 32.D 33.A 34.B 35.D 36.C 37.B 38.C 39.C 40.A 41.D 42.A 43.D 44.A 45.C 46.A 47.D 48.C 49.C 50.A