双向免疫扩散试验选择（）

A.琼脂糖

B.琼脂糖珠4B

C.聚乙二醇

D.硫酸铵

E.聚丙烯酰胺

What can we learn from the approach to scientific research in other cultures Consider British science. In the 1980s to mid-1990s, the United Kingdom consistently (67) many more populous countries in (68) number of papers produced and citations received per paper in science, medicine and engineering. During the 20th century, the United Kingdom (69) more major international scientific prizes per capita than any other nation—about 10% of all such (70) .
Many explanations have been (71) for this success. Some British attribute it (72) a superiority of intellect and character. (73) British scientists are a more elite group than American scientists, (74) selective pressure throughout secondary and undergraduate education. My experience in the United Kingdom (75) me to think that another significant reason for this (76) is the British style of scientific investigation. I must (77) that at first I was frustrated by the slower (78) of research in the United Kingdom in (79) with that in the United States. Having recently completed my doctoral research in the intense environment (80) of many U. S. universities, I thought that the greater relative emphasis that the British placed on thinking (81) doing was at best misguided, and at worst, lazy. (82) , I soon saw the advantages of being more selective (83) which problems to work on, which experiments to (84) , and which approach would best (85) the results. There were many occasions where I experienced such (86) contrasts in the approach to scientific research in different cultures. And the experience did enrich my intellectual life indeed.

A. Now that
B. And
C. Because
D. Yet