Because of the lack of funds the tunnel project has already fallen behind .A. situationB.

问题补充：

Because of the lack of funds, the tunnel project has already fallen behind .

A. situation

B. speed

C. insurance

D. schedule

答案：

A. situation

B. speed

C. insurance

(答案→)D. schedule

解析：句意：因为缺乏资金,隧道工程已经迟于预订计划。A. situation情况； B. speed 速度； C. insurance保险； D. schedule计划。behind schedule是一个固定短语，意为比原计划慢。