2. 下列关于实验的描述不正确的是

A．用灭活的病毒或聚乙二醇诱导效应B细胞和骨髓瘤细胞融合

B．利用同位素标记法研究光合作用中碳原子的转移途径

C．双缩脲试剂A、B混合均匀后加入豆浆中，溶液立即显紫色

D．利用饲喂法研究甲状腺激素的生理作用

有一个选项是符合题意的。)

1．科学家初步研制出H5N1型禽流感疫苗，应用前必须进行动物实验检测其效果，将未感染H5N1型病毒的一群健康小鸡分为A、B两组，实验过程和结果如下图所示：下列相关分析错误的是

A．B组小鸡全部死亡是因为体内没有足够抗 H5N1型病毒的抗体

B．B组小鸡全部死亡是因为体内没有控制产生抗H5N1型病毒抗体的基因

C．A组小鸡存活是H5N1型疫苗和有关基因相互作用的结果

D．A组小鸡存活最可能是体液免疫和细胞免疫共同作用的结果

20.-Would you please find a world map which is drawn to a scale of 　　　　　　　　　　　.

-Yes,sir.Here you are.

A.one out of ten thousand　　　 B.one in ten thousands

C.one to ten thousand　　　　　 D.one of ten thousands

19. __________ people in the world are sending information by E-mail every day.

A.Tens of thousands of　 B. Ten thousands of　　 C. Several millions　　 D. Many million

18. ___________ of the land in the district _______ covered with trees and grass.

A. Two fifth; is　　　　　 B. Two fifth; are　　　 C. Two fifths; is　　　 D. Two fifths, are

17.You can have _________　　　 try if you fail _______　　 _ time.

A.the second,the first　　　 B.a second,a first　　　 C.the second,a first　 D.a second,the first

16.-How many pencils would you like,Madame?

-Well,I want_________of these.

A.three dozen　　　　　　 B.three dozen of　　　 C.three dozens　　　　 D.three dozens of

15.In 1948, the place where his father had been buried was finally discovered, marked only by _____, on a simple stone.

A, a 43-number　　　　　 B, the number 43^rd 　　C, the number 43　　　 D, the 43 number

14.-What kind of person do you want to help you?

-______ always trying his best and never giving up in time of difficulty.

A.That　　　 　　　　　　　 B.The one　　　　　 C.One　 　　　　　　D.Such

13.-I wonder why the couple often eat out?

-Oh,it is sai that_________of them can cook.

A.none　　　　　　　 B.not both　　　　her　　　　　　 D.not all