the whole process for the studies of cancer took more than a year, the technology is moving so fast that it will soon take just weeks．
A. How
B. Because
C. If
D. While
网友回答
A. How
B. Because
C. If
(答案→)D. While
解析：句意：虽然研究癌症的整个过程已经耗时近一年多，但是技术发展如此之快以至于很快就用不了几周的时间就有进展了。How 怎样，引导方式状语从句；Because因为，引导原因状语从句；If引导条件状语从句；While 当….时，尽管，引导让步状语从句。
考点: 考查连词的用法。