The research results show that the earth goes a little faster it is closer to the sun.A. a

问题补充：

The research results show that the earth goes a little faster it is closer to the sun.

A. as though

B. so that

C. than

D. when

答案：

A. as though

B. so that

C. than

(答案→)D. when

解析：句意：研究结果表明当地球越接近太阳时它运行的更快一些。when 当…时候，引导时间状语从句。