James was sleepy he stayed up late to finish his project.A. AsB. SinceC. UnlessD. Althou

问题补充：

James was sleepy, he stayed up late to finish his project.

A. As

B. Since

C. Unless

D. Although

答案：

A. As

B. Since

C. Unless

D. Although

解析：选D。考查状语从句。句意: 尽管James很困, 但是他熬夜完成了项目。although引导让步状语从句, “尽管”。as也可以引导让步状语从句, 但是必须倒装。