So quickly are science and technology advancing is a possibility today may be a reality t

问题补充：

So quickly are science and technology advancing is a possibility today may be a reality tomorrow.

A. which

B. what

C. that which

D. that what

答案：

A. which

B. what

C. that which

(答案→)D. that what

解析：D 考察典型句式和名词性从句。So…that引导的是结果状语从句，so位于句首引起部分倒装，在结果状语从句中有一个由what引导的主语从句。