I saw Jane，she was picking cotton in the field.
A. For the first time
B. At the first time
C. By the first time
D. The first time
网友回答
A. For the first time
B. At the first time
C. By the first time
(答案→)D. The first time
解析：四个选项中，只有the first time可起连词作用，用以引导时间状语从句；另三个都是介词短语。