He at once when I promised to help him.A. cheered upB. gave upC. lighted upD. turned up

问题补充：

He at once when I promised to help him.

A. cheered up

B. gave up

C. lighted up

D. turned up

答案：

(答案→)A. cheered up

B. gave up

C. lighted up

D. turned up

解析：本题考查短语辨析。A高兴起来；B放弃；C点亮；D出现。句意：当我答应帮助他，他立刻高兴起来。